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STREAMS Manual

Description: OpenSS7 Online Manuals

A PDF version of this document is available here.

Linux Fast-STREAMS

Linux Fast-STREAMS Installation and Reference Manual

About This Manual

This is Edition 4, last updated 2008-10-31, of The Linux Fast-STREAMS Installation and Reference Manual, for Version 0.9.2 release 4 of the Linux Fast-STREAMS package.

Preface

Notice

This package is released and distributed under the AGPL (see GNU Affero General Public License). Please note, however, that there are different licensing terms for the manual pages and some of the documentation (derived from OpenGroup1 publications and other sources). Consult the permission notices contained in the documentation for more information.

This manual is released under the FDL (see GNU Free Documentation License) with no sections invariant.

Abstract

This manual provides a Installation and Reference Manual for Linux Fast-STREAMS.

Objective

The objective of this manual is to provide a guide for the STREAMS programmer when developing STREAMS modules, drivers and application programs for Linux Fast-STREAMS.

This guide provides information to developers on the use of the STREAMS mechanism at user and kernel levels.

STREAMS was incorporated in UNIX System V Release 3 to augment the character input/output (I/O) mechanism and to support development of communication services.

STREAMS provides developers with integral functions, a set of utility routines, and facilities that expedite software design and implementation.

Intent

The intent of this manual is to act as an introductory guide to the STREAMS programmer. It is intended to be read alone and is not intended to replace or supplement the Linux Fast-STREAMS manual pages. For a reference for writing code, the manual pages (see STREAMS(9)) provide a better reference to the programmer. Although this describes the features of the Linux Fast-STREAMS package, OpenSS7 Corporation is under no obligation to provide any software, system or feature listed herein.

Audience

This manual is intended for a highly technical audience. The reader should already be familiar with Linux kernel programming, the Linux file system, character devices, driver input and output, interrupts, software interrupt handling, scheduling, process contexts, multiprocessor locks, etc.

The guide is intended for network and systems programmers, who use the STREAMS mechanism at user and kernel levels for Linux and UNIX system communication services.

Readers of the guide are expected to possess prior knowledge of the Linux and UNIX system, programming, networking, and data communication.

Revisions

Take care that you are working with a current version of this manual: you will not be notified of updates. To ensure that you are working with a current version, contact the Author, or check The OpenSS7 Project website for a current version.

A current version of this manual is normally distributed with the Linux Fast-STREAMS package.

Version Control

     STREAMS.texi,v
     Revision 0.9.2.45  2008-09-20 11:04:35  brian
     - added package patchlevel
     
     Revision 0.9.2.44  2008-08-03 06:03:36  brian
     - protected agains texinfo commands in log entries
     
     Revision 0.9.2.43  2008/07/27 08:49:17  brian
     - no invariant sections, more libtool ignores
     
     Revision 0.9.2.42  2008-04-28 12:54:00  brian
     - update file headers for release
     
     Revision 0.9.2.41  2008-04-25 11:50:49  brian
     - updates to AGPLv3
     
     Revision 0.9.2.40  2007/12/15 20:19:44  brian
     - updates
     
     Revision 0.9.2.39  2007/11/06 10:27:04  brian
     - miscellaneous corrections
     
     Revision 0.9.2.38  2007/08/12 06:44:32  brian
     - updated licenses in manuals
     
     Revision 0.9.2.37  2007/03/17 08:31:56  brian
     - corrected formatting problems
     
     Revision 0.9.2.36  2007/02/28 06:30:55  brian
     - updates and corrections, #ifdef instead of #if
     
     Revision 0.9.2.35  2007/01/02 16:32:03  brian
     - updates for release, disable streams-bcm by default
     
     Revision 0.9.2.34  2006/12/31 13:26:37  brian
     - documentation updates for release
     
     Revision 0.9.2.33  2006/09/18 01:06:57  brian
     - updated manuals and release texi docs
     
     Revision 0.9.2.32  2006/08/28 10:47:05  brian
     - correction
     
     Revision 0.9.2.31  2006/08/28 10:32:54  brian
     - updated references
     
     Revision 0.9.2.30  2006/08/27 12:26:58  brian
     - finalizing auto release files
     
     Revision 0.9.2.29  2006/08/26 18:31:44  brian
     - handle long urls
     
     Revision 0.9.2.28  2006/08/26 09:18:27  brian
     - better release file generation
     
     Revision 0.9.2.27  2006/08/23 11:00:41  brian
     - added preface, corrections and updates for release
     
     Revision 0.9.2.26  2006/08/22 12:36:49  brian
     - udpates to documentation, tweaks to Stream head
     
     Revision 0.9.2.25  2006/03/22 10:02:04  brian
     - added makefile target index
     
     Revision 0.9.2.24  2006/03/03 10:57:11  brian
     - 32-bit compatibility support, updates for release
     
     Revision 0.9.2.23  2005/09/15 13:03:08  brian
     - added new graphics and updates
     
     Revision 0.9.2.22  2005/07/08 13:16:11  brian
     - updates to documentation
     
     Revision 0.9.2.21  2005/06/24 13:38:59  brian
     - added troubleshooting section to manuals
     
     Revision 0.9.2.20  2005/05/14 08:34:34  brian
     - copyright header correction
     
     Revision 0.9.2.19  2005/04/15 00:58:31  brian
     - working up documentation
     
     Revision 0.9.2.18  2005/04/14 08:06:09  brian
     - added figures
     
     Revision 0.9.2.17  2005/04/12 09:28:59  brian
     - corrections
     
     Revision 0.9.2.16  2005/04/11 20:48:41  brian
     - documentation updates and corrections
     
     Revision 0.9.2.15  2005/03/15 12:06:58  brian
     - Updated texinfo documentation.
     
     Revision 0.9.2.14  2005/03/15 00:56:42  brian
     - Updated version numbering in texinfo files.
     
     Revision 0.9.2.13  2005/03/15 00:51:34  brian
     - Updated version numbering in texinfo files.
     
     Revision 0.9.2.12  2005/02/17 22:57:34  brian
     - Some cross-reference corrections.
     
     Revision 0.9.2.11  2005/02/17 11:34:53  brian
     - Corrected some more texi problems.
     
     Revision 0.9.2.10  2005/01/24 11:57:57  brian
     - Updated texinfo headers.
     
     Revision 0.9.2.9  2004/12/19 15:15:02  brian
     - Corrected include position.
     
     Revision 0.9.2.8  2004/12/17 04:02:46  brian
     - Improving spec files.
     
     Revision 0.9.2.7  2004/11/06 10:24:35  brian
     - Updated documentation.
     
     Revision 0.9.2.6  2004/08/22 07:28:53  brian
     - Converted to shared common files.
     
     Revision 0.9.2.5  2004/08/22 06:17:50  brian
     - Checkin on new working branch.
     
     Revision 0.9.2.4  2004/08/15 19:59:29  brian
     - Build system updates.
     
     Revision 0.9.2.3  2004/05/29 08:28:01  brian
     - Working up stable release.
     
     Revision 0.9.2.2  2004/03/15 07:59:39  brian
     - Working up manual pages.
     
     Revision 0.9.2.1  2004/03/13 05:46:34  brian
     - Working up more documentation.

ISO 9000 Compliance

Only the TeX, texinfo, or roff source for this manual is controlled. An opaque (printed, postscript or portable document format) version of this manual is an UNCONTROLLED VERSION.

Disclaimer

OpenSS7 Corporation disclaims all warranties with regard to this documentation including all implied warranties of merchantability, fitness for a particular purpose, non-infringement, or title; that the contents of the manual are suitable for any purpose, or that the implementation of such contents will not infringe on any third party patents, copyrights, trademarks or other rights. In no event shall OpenSS7 Corporation be liable for any direct, indirect, special or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with any use of this manual or the performance or implementation of the contents thereof.

OpenSS7 Corporation reserves the right to revise this software and documentation for any reason, including but not limited to, conformity with standards promulgated by various agencies, utilization of advances in the state of the technical arts, or the reflection of changes in the design of any techniques, or procedures embodied, described, or referred to herein. OpenSS7 Corporation is under no obligation to provide any feature listed herein.

U.S. Government Restricted Rights

If you are licensing this Software on behalf of the U.S. Government ("Government"), the following provisions apply to you. If the Software is supplied by the Department of Defense ("DoD"), it is classified as "Commercial Computer Software" under paragraph 252.227-7014 of the DoD Supplement to the Federal Acquisition Regulations ("DFARS") (or any successor regulations) and the Government is acquiring only the license rights granted herein (the license rights customarily provided to non-Government users). If the Software is supplied to any unit or agency of the Government other than DoD, it is classified as "Restricted Computer Software" and the Government's rights in the Software are defined in paragraph 52.227-19 of the Federal Acquisition Regulations ("FAR") (or any successor regulations) or, in the cases of NASA, in paragraph 18.52.227-86 of the NASA Supplement to the FAR (or any successor regulations).

Acknowledgements

As with most open source projects, this project would not have been possible without the valiant efforts and productive software of the Free Software Foundation and the Linux Kernel Community.

Sponsors

Funding for completion of the OpenSS7 Linux Fast-STREAMS package was provided in part by:

OpenSS7 Corporation

Additional funding for The OpenSS7 Project was provided by:

OpenSS7 Corporation
Lockheed Martin Co.
Motorola
HOB International
Comverse Ltd.
Sonus Networks Inc.
France Telecom
SS8 Networks Inc.
Nortel Networks
Verisign
eServGlobal (NZ) Pty Ltd.
NetCentrex S. A.
SysMaster Corporation
GeoLink SA
AirNet Communications
TECORE
Tumsan Oy
Vodare Ltd.
Excel Telecommunications

Contributors

The primary contributor to the OpenSS7 Linux Fast-STREAMS package is Brian F. G. Bidulock. The following is a list of significant contributors to The OpenSS7 Project:

− Per Berquist
− John Boyd
− Chuck Winters
− Peter Courtney
− Tom Chandler
− Gurol Ackman
− Kutluk Testicioglu
− John Wenker
− Others

Authors

The authors of the OpenSS7 Linux Fast-STREAMS package include:

Brian Bidulock

See Author Index, for a complete listing and cross-index of authors to sections of this manual.

Maintainer

The maintainer of the OpenSS7 Linux Fast-STREAMS package is:

Brian Bidulock

Please send bug reports to bugs@openss7.org using the send-pr script included in the package, only after reading the BUGS file in the release, or See Problem Reports.

Web Resources

The OpenSS7 Project provides a website dedicated to the software packages released by the OpenSS7 Project.

Bug Reports

Please send bug reports to bugs@openss7.org using the send-pr script included in the Linux Fast-STREAMS package, only after reading the BUGS file in the release, or See Problem Reports. You can access the OpenSS7 GNATS database directly via the web, however, the preferred method for sending new bug reports is via mail with the send-pr script.

Mailing Lists

The OpenSS7 Project provides a number of general discussion Mailing Lists for discussion concerning the OpenSS7 Linux Fast-STREAMS package as well as other packages released by The OpenSS7 Project.

These are mailman mailing lists and so have convenient web interfaces for subscribers to control their settings. See http://www.openss7.org/mailinglist.html.

The mailing lists are as follows:

openss7
The openss7 mailing list is for general enquiries, information exchange and announcements regarding the OpenSS7 Project. This is our original mailing list and takes the highest amount of traffic.
openss7-announce
The openss7-announce mailing list is for announcements related to the OpenSS7 Project. This list will accept announcements posted by subscribers. Subscribe to this list if you are interested in announcements from the OpenSS7 Project, subscribers and sponsors, related to the OpenSS7 Project or STREAMS, SS7, SIGTRAN or SCTP in general.
openss7-cvs
The openss7-cvs mailing list is for automatic CVS log reporting. You must get permission of the owner to subscribe to this list. Subscribers are not allowed to post to this list, this is merely for distributing notification of changes to the CVS repository.h
openss7-develop
The openss7-develop mailing list is for email exchange related to the development projects under the OpenSS7 Project. This includes development requests, proposals, requests for comment or proposal. Subscribe to this list if you are interested in ongoing development details regarding the OpenSS7 Project.
openss7-test
The openss7-test mailing list is for email exchange related to the testing of code under the OpenSS7 Project. This specifically relates to conformance testing, verification testing, interoperability testing and beta testing. Subscribe to this list if you are interested in participating in and receiving ongoing details of test activities under the OpenSS7 Project.
openss7-bugs
The openss7-bugs mailing list is specifically tailored to bug tracking. The mailing list takes a feed from the OpenSS7 GNATS bug tracking system and accepts posting of responses to bug reports, tracking and resolution. Subscribe to this list if you are interested in receiving detailed OpenSS7 release code bug tracking information. This list is not archived; for historical information on problem reports, see our GNATS databases.
openss7-updates
The openss7-updates mailing list provides updates on OpenSS7 Project code releases and ongoing activities. Subscribers are not allowed to post to this list; this list is for official OpenSS7 Project announcements only. Subscribe to this list if you are interested in receiving updates concerning official releases and activities of the OpenSS7 Project.
openss7-streams
The openss7-streams mailing list is for email exchange related to the STREAMS development projects under the OpenSS7 Project. This includes development requests, proposals, requests for comment or proposal. Subscribe to this list if you are interested in ongoing development details regarding the OpenSS7 Project STREAMS components.
linux-streams
The linux-streams mailing list is for mail exchange related to Linux Fast-STREAMS or Linux STREAMS. This includes patches, development requests, proposals, requests for comment or proposal. Subscribe to this list if you are interested in ongoing development details regarding the STREAMS for Linux components. This is the the new (September 2006) home of the linux-streams list formerly of <gsyc.escet.urjc.es>.
Spam

To avoid spam being sent to the members of the OpenSS7 mailing list(s), we have blocked mail from non-subscribers. Please subscribe to the mailing list before attempting to post to them. (Attempts to post when not subscribed get bounced.)

As an additional measure against spam, subscriber lists for all OpenSS7 mailing lists are not accessible to non-subscribers; for most lists subscriber lists are only accessible to the list administrator. This keeps your mailing address from being picked off our website by bulk mailers.

Acceptable Use Policy

It is acceptable to post professional and courteous messages regarding the OpenSS7 package or any general information or questions concerning STREAMS, SS7, SIGTRAN, SCTP or telecommunications applications in general.

Large Attachments

The mailing list is blocked from messages of greater than 40k. If you have attachments (patches, test programs, etc.) and you mail them to the list, it will bounce to the list administrator. If you are interested in making your patches, test programs, test results or other large attachments available to the members of the mailing list, state in the message that you would like them posted and the list administrator will place them in the mail archives.

Quick Start Guide

Linux Fast-STREAMS

Package streams-0.9.2.4 was released under AGPLv3 2008-10-31.

The OpenSS7 Linux Fast-STREAMS package is a High-Performance STREAMS framework for Linux that is compatible with SVR 4.2 MP STREAMS and a host of other commercial UNIX® STREAMS implementations, with complete debugging and production release capabilities. It is as a high-performance, production replacement for the buggy and now deprecated Linux STREAMS (LiS).

The Linux Fast-STREAMS package includes kernel modules, SVR 4.2 STREAMS drivers, modules, libraries, utilities, test programs, daemons, and development environment for the development and execution of STREAMS modules and drivers under Linux Fast-STREAMS. It is completely documented with over four hundred (435) manual pages, and three (3) major print set manuals.

The package configures, compiles, installs and builds rpms or debs for a wide range of Linux rpm(1)- or dpkg(1)-based distributions, and can be used on production kernels without patching, recompiling or tainting the kernel. Its small run-time footprint makes the release suitable for embedded targets.

This distribution is only currently applicable to Linux 2.4 and 2.6 kernels and was targeted at ix86, x86_64, ppc and ppc64 architectures, but should build and install for other architectures as well.

Release

This is the streams-0.9.2.4 package, released 2008-10-31. This ‘0.9.2.4’ release, and the latest version, can be obtained from the download area of The OpenSS7 Project website using a command such as:

     $> wget http://www.openss7.org/tarballs/streams-0.9.2.4.tar.bz2

The release is available as an autoconf(1) tarball, src.rpm or dsc, as a set of binary rpms or debs, or as a yum(8) or apt(8) repository. See the download page for the autoconf(1) tarballs, src.rpms, dscs, or repository access instructions. See the streams package page for tarballs, source and binary packages.

Please see the NEWS file for release notes and history of user visible changes for the current version, and the ChangeLog file for a more detailed history of implementation changes. The TODO file lists features not yet implemented and other outstanding items.

Please see the INSTALL, INSTALL-streams and README-make, files (or see Installation) for installation instructions.

When working from cvs(1) or git(1), please see the README-cvs, file (or see Downloading from CVS). An abbreviated installation procedure that works for most applications appears below.

This release of the package is published strictly under Version 3 of the GNU Affero Public License which can be found in the file COPYING. Package specific licensing terms (if any) can be found in the file LICENSES. Please respect these licensing arrangements. If you are interested in different licensing terms, please contact the copyright holder, or OpenSS7 Corporation <sales@openss7.com>.

See README-alpha (if it exists) for alpha release information.

Prerequisites

The quickest and easiest way to ensure that all prerequisites are met is to download and install this package from within the OpenSS7 Master Package, openss7-0.9.2.G, instead of separately.

Prerequisites for the Linux Fast-STREAMS package are as follows:

  1. Linux distribution, somewhat Linux Standards Base compliant, with a 2.4 or 2.6 kernel and the appropriate tool chain for compiling out-of-tree kernel modules. Most recent Linux distributions are usable out of the box, but some development packages must be installed. For more information, see Compatibility.

    − A fairly LSB compliant GNU/Linux distribution.2
    − Linux 2.4 kernel (2.4.10 - 2.4.27), or
    − Linux 2.6 kernel (2.6.3 - 2.6.26);
    − glibc2 or better.
    − GNU groff (for man pages).3
    − GNU texinfo (for info files).
    − GNU bison and flex (for config programs).
    − net-snmp (for SNMP agents).4

When configuring and building multiple OpenSS7 Project release packages, place all of the source packages (unpacked tarballs) at the same directory level and all build directories at the same directory level (e.g. all source packages under /usr/src).

When installing packages that install as kernel modules, it is necessary to have the correct kernel development package installed. For the following distributions, use the following commands:

     Ubuntu:  $> apt-get install linux-headers
     Debian:  $> apt-get install kernel-headers
     Fedora:  $> yum install kernel-devel

You also need the same version of gcc(1) compiler with which the kernel was built. If it is not the default, add ‘CC=kgcc’ on the line after ‘./configure’, for example:

     $> ../streams-0.9.2.4/configure CC='gcc-3.4'

Installation

The following commands will download, configure, build, check, install, validate, uninstall and remove the package:

     $> wget http://www.openss7.org/tarballs/streams-0.9.2.4.tar.bz2
     $> tar -xjvf streams-0.9.2.4.tar.bz2
     $> mkdir build
     $> pushd build
     $> ../streams-0.9.2.4/configure --enable-autotest
     $> make
     $> make check
     $> sudo make install
     $> sudo make installcheck
     $> sudo make uninstall
     $> popd
     $> sudo rm -rf build
     $> rm -rf streams-0.9.2.4
     $> rm -f streams-0.9.2.4.tar.bz2

If you have problems, try building with the logging targets instead. If the make of a logging target fails, an automatic problem report will be generated that can be mailed to The OpenSS7 Project.5 Installation steps using the logging targets proceed as follows:

     $> wget http://www.openss7.org/tarballs/streams-0.9.2.4.tar.bz2
     $> tar -xjvf streams-0.9.2.4.tar.bz2
     $> mkdir build
     $> pushd build
     $> ../streams-0.9.2.4/configure --enable-autotest
     $> make compile.log
     $> make check.log
     $> sudo make install.log
     $> sudo make installcheck.log
     $> sudo make uninstall.log
     $> popd
     $> sudo rm -rf build
     $> rm -rf streams-0.9.2.4
     $> rm -f streams-0.9.2.4.tar.bz2

See README-make for additional specialized make targets.

For custom applications, see the INSTALL and INSTALL-streams files or the see Installation, as listed below. If you encounter troubles, see Troubleshooting, before issuing a bug report.

Brief Installation Instructions

The Linux Fast-STREAMS package is available from the downloads area of The OpenSS7 Project website using a command such as:

     $> wget http://www.openss7.org/tarballs/streams-0.9.2.4.tar.bz2

Unpack the tarball using a command such as:

     $> tar -xjvf streams-0.9.2.4.tar.bz2

The tarball will unpack into the relative subdirectory named after the package name: streams-0.9.2.4.

The package builds using the GNU autoconf utilities and the configure script. To build the package, we recommend using a separate build directory as follows:

     $> mkdir build
     $> cd build
     $> ../streams-0.9.2.4/configure

In general, the package configures and builds without adding any special options to the configure script. For general options to the configure script, see the GNU INSTALL file in the distribution:

     $> less ../streams-0.9.2.4/INSTALL

For specific options to the configure script, see the INSTALL-streams file in the distribution, or simply execute the configure script with the --help option like so:

     $> ../streams-0.9.2.4/configure --help

After configuring the package, the package can be compiled simply by issuing the ‘make’ command:

     $> make

Some specialized makefile targets exists, see the README-make file in the distribution or simply invoke the ‘help’ target like so:

     $> make help | less

After successfully building the package, the package can be checked by invoking the ‘check’ make target like so:

     $> make check

After successfully checking the package, the package can be installed by invoking the ‘install’ make target (as root) like so:

     $> sudo make install

The test suites that ship with the package can be invoked after the package has been installed by invoking the ‘installcheck’ target. This target can either be invoked as root, or as a normal user, like so:

     $> make installcheck

(Note: you must add the --enable-autotest flag to configure, above for the test suites to be invoked with ‘make installcheck’.)

The package can be cleanly removed by invoking the ‘uninstall’ target (as root):

     $> sudo make uninstall

Then the build directory and tarball can be simply removed:

     $> cd ..
     $> rm -rf build
     $> rm -rf streams-0.9.2.4
     $> rm -f streams-0.9.2.4.tar.bz2

Detailed Installation Instructions

More detailed installation instructions can be found in the Installation, contained in the distribution in ‘text’, ‘info’, ‘html’ and ‘pdf’ formats:

     $> cd ../streams-0.9.2.4
     $> less doc/manual/streams.txt
     $> lynx doc/manual/streams.html
     $> info doc/manual/streams.info
     $> xpdf doc/manual/streams.pdf

The ‘text’ version of the manual is always available in the MANUAL file in the release.

The current manual is also always available online from The OpenSS7 Project website at:

     $> lynx http://www.openss7.org/streams_manual.html

1 Introduction

This manual documents the design, implementation, installation, operation and future development schedule of the Linux Fast-STREAMS package.

1.1 Overview

This manual documents the design, implementation, installation, operation and future development of the Linux Fast-STREAMS package.

1.2 Organization of this Manual

This manual is organized (loosely) into several sections as follows:

Introduction. This introduction
Objective. Objective of the package
Reference. Contents of the package
Development. Developing with the package
Porting. Porting to the package
Conformance. Conformance of the package
Releases. Releases of the package
Installation. Installation of the package
Troubleshooting. Troubleshooting of the package

1.3 Conventions and Definitions

This manual uses texinfo typographic conventions.

2 Objective

2.1 Background

STREAMS derives from Dennis Ritchie's original paper,6 was incorporated into the UNIX® System V Release 3 operating system, replaced the terminal input-output subsystem, pipes and FIFOs in UNIX® System V Release 4, and was improved in the USL release of the UNIX® System V Release 4.2 operating system.

Today, STREAMS is a part of every major branded UNIX® variant, such as AIX®, HP-UX®, IRIX®, MacOT®, OSF/1®, Solaris®, SUPER-UX®, UnixWare®, UXP/V®, and including many UNIX-like operating systems and popular embedded RTOS, but with the notable exception of Berkeley System Distribution releases, variants and offshoots, and Linux.

2.2 What is STREAMS?

STREAMS is a flexible framework for communication between a user level process and a kernel resident driver. It encompasses a set of kernel system calls providing a user-kernel interface that is backward compatible with the traditional character device driver interface, as well as a set of STREAMS driver and module entry points forming a driver-kernel interface. STREAMS also provides a rich set of kernel utility functions for the development and implementation of kernel-resident drivers and modules. STREAMS prompted the specification of the DDI/DKI which is an architecture independent driver-kernel interface that provides a standardized set of kernel functions (beyond just STREAMS) for the development of device and software drivers.

STREAMS provides a reconfigurable full-duplex communications path between user level process and kernel resident driver, termed a Stream. Modules can be inserted in the path between the user and driver under user level control. Streams can be linked across multiplexers under user control to form complex (yet reconfigurable) topologies of user level processes and drivers.

Communication of control and data information along a Stream is accomplished by message passing. There is no direct function call interface between components of a Stream. A Stream exists within the STREAMS framework inside the kernel and extend from the user-kernel interface to the kernel driver interface. Each component of a Stream consists of a pair of queues used to pass messages in the upstream direction to the kernel-user interface; or downstream, the kernel-driver interface.

At the kernel-user end of the Stream is a component called the Stream head. As with all components of a Stream, the Stream head consists of a queue pair and a specialized set of procedures. The Stream head procedures are responsible for converting between the system call interface presented to users and the message passing mechanism within the Stream.

At the kernel-driver end of the Stream is the Stream end. The Stream end also contains a queue pair and a set of procedures. The Stream end (or simply driver) procedures are responsible for converting between the message passing mechanism within the Stream and the actions and events of a hardware (or pseudo-) device.

Intermediate components within the Stream are called Modules. Modules consist of a queue pair for passing messages upstream and downstream, as well as a set of procedures for processing messages. Modules can be pushed onto the module stack between the Stream head and Stream end using a set of standardized input-output control commands.

In support of topologies more complex than these simple linear segments, STREAMS also provides a specialized Stream end (driver) called a Multiplexing driver. A Multiplexing driver has the ability to open multiple Streams to its upper interface (multiplexer) as well as linking multiple Streams beneath its lower interface (multiplexer). Again, a standardized set of input-output controls provide the user with the ability to configure a Multiplexing driver.

2.3 Why STREAMS?

With the ability to open multiple Streams to a driver, push and pop modules to and from the module stack on a Stream, and to link any Stream under a multiplexing driver–all under user control using standardized input-output controls–allows STREAMS to configure complex topologies to form protocol stacks.

Almost all specialized standard telecommunications software developed since 1990 was developed to run on STREAMS. This is for several reasons:

  • Since 1990, STREAMS and the associated DDI/DKI has been, and remains, the only way to incorporate OEM protocol stacks into mainstream UNIX® system kernels.
  • The original UNIX System Laboratories (later X/Open then later the OpenGroup) support for ITU-T developed OSI protocols, makes STREAMS amenable to an open model for development for ITU-T protocols. (ITU-T, formerly CCITT, is the International Telecommunications Union – Telephone Sector responsible for international telephone standards, and original developers of the OSI model.)

As a result, there is a significant body of commercial software implementing telecommunications protocol stacks that was developed, tested, validated, conformance tested, field verified, to run on STREAMS: and is still running on STREAMS.

The cost of reimplementation, retesting, revalidation, redoing conformance testing, and field re-verification, would likely be prohibitive: after all, the point of Linux is reducing cost, is it not?

2.4 Why STREAMS for Linux?

The Linux kernel was not developed with STREAMS in mind. For TPI/IP networking, Linux originally followed in the footsteps of the BSD NET2 release. Currently, the implementation of TCP/IP in the Linux kernel has long departed from the classical BSD organization and exhibits characteristics unique to the GNU/Linux operating system. For character device and terminal input-output, Linux follows closely the SVR 3 pre-STREAMS approach to pipes, FIFOs and terminal subsystem. The terminal subsystem implementation, too, has become unique to GNU/Linux.

Therefore, from the perspective of TCP/IP networking and Terminal I/O, there would be little reason to provide STREAMS for Linux. That is, if it were not for the body of software supporting OSI and telecommunications protocols based solely on STREAMS, for which Linux has little or no support.

So, the answer to the question, "Why STREAMS for Linux?" is: so that a GNU/Linux platform can enjoy the same wealth of telecommunications and OSI protocol stacks otherwise only available to big-iron UNIX®. Without STREAMS, Linux is probably just another BSD, and probably not a very good one.

2.5 History of STREAMS for Linux

In the mid-90's, GCOM Inc. embarked on development on an open source implementation of STREAMS called Linux STREAMS (LiS), likely driven by its use for porting existing OSI protocol stacks to Linux. In 2000, The OpenSS7 Project abandoned using the Linux networking model for implementation of the Signalling System No. 7 protocol (primarily due to the lack of support for the full BSD networking model under Linux) and switched to using STREAMS as the basis for all future development. The GCOM LiS release (2.2 at the time) was used as the STREAMS package. Over the span of the next 5 years, (and not surprisingly given the body of software), almost all Signalling System No. 7 products released on Linux used LiS for STREAMS. In 2005, Dave Grothe (the G in GCOM) announced that he would no longer be maintaining or developing LiS subsequent to the 2.18.0 release, stranding many users of the package.

Later in 2005, after briefly maintaining two GPL'ed releases of LiS, (2.18.1 and 2.18.2), The OpenSS7 Project release (after two years of development) the streams-0.7a.4 package: a reimplementation of SVR 4.2 STREAMS with compatibility modules for all major UNIX® releases, called Linux Fast-STREAMS. Linux Fast-STREAMS was intended as a POSIX/SUSv3 XSR conforming, high performance, production grade, replacement for LiS, suitable for mainline Linux adoption, and a better foundation on which to base SIGTRAN, VoIP, ISDN and SS7 protocol stacks developed under the The OpenSS7 Project, as well as a better foundation for porting commercial UNIX® OEM implementations to Linux. It is the streams-0.9.2.4 package that contains the documentation you are reading now.

2.6 Why Fast?

After working with LiS releases for over 3 years, in late 2003, The OpenSS7 Project decided to begin implementation of a replacement for LiS, because of a number of shortcomings of the LiS releases:

  1. unsuitable for mainline kernel adoption due to coding style and organization;
  2. poorly adapted to distribution production kernels;
  3. is unsuitable for packaging and repeatability;
  4. portability objective unsuitable for mainline kernel adoption;
  5. ports form the same baseline obfuscate the code;
  6. performs poorly due to portability and coding style;
  7. code bloat and over sized memory footprint;
  8. redundant debug statements obscuring defects and obfuscating code;
  9. overuse of semaphores;
  10. contains serious races and not suitable for threaded applications;
  11. does not conform to mainstream UNIX® implementations;
  12. does not conform to POSIX or any release of the Single UNIX Specification;
  13. limited set of standard drivers and modules;
  14. limited set of diagnostic and administrative utilities;
  15. limited test programs;
  16. poorly documented.

The replacement, named Linux Fast-STREAMS, was to correct all of these difficulties, and, by the initial ‘streams-0.7a.4’ release, was:

  1. completely Lindented and follows kernel coding practises;
  2. automatically adapts to production kernels with autoconf;
  3. packages itself into LSB compliant RPMs and DEBs;
  4. designed and implemented specifically for GNU/Linux;
  5. no ports considered;
  6. over twice the performance;
  7. less than one-eighth of the memory footprint;
  8. proper programming by assertion;
  9. proper use of lightweight spin locks;
  10. race free locking strategies and synchronization;
  11. compatible with all mainstream UNIX® implementations;
  12. conforms to POSIX/SUSv3 XSR;
  13. complete set of standard drivers and modules;
  14. complete set of diagnostic and administrative utilities;
  15. integrated set of conformance test suites;
  16. fully documented.

Many specific difficulties encountered with LiS not repeated by Linux Fast-STREAMS are contained in the COMPATIBILITY section of most of the manual pages.

3 Reference

3.1 Files

The following kernel modules are installed by Linux Fast-STREAMS in the /lib/modules/2.4.20-28.7/streams/directory, with either a ‘.o’ or ‘.ko’ extension. 7

specfs
This kernel module contains the STREAMS Special Shadow Filesystem. See specfs(5) for more information.
streams
This kernel module contains the STREAMS scheduler, utility functions, and STREAMS Device Driver Interface/Driver Kernel Interface (DDI/DKI). See STREAMS(9) for more information.
streams-fifo
This kernel module contains the fifo STREAMS driver. This is a standard STREAMS driver, but is also used by the conformance and validation test suite. See fifo(4) for more information.
streams-sad
This kernel module contains the sad STREAMS driver. This is the standard STREAMS Administrative Driver. See sad(4) for more information.
streams-nsdev
This kernel module contains the nsdev STREAMS driver. This is a Linux Fast-STREAMS specific driver. See nsdev(4) for more information.
streams-echo
This kernel module contains the echo STREAMS driver. This is a standard STREAMS driver, but is also used by the conformance and validation test suite. See echo(4) for more information.
streams-mux
This kernel module contains the mux STREAMS driver. This is a standard STREAMS driver< but is also used by the conformance and validation test suite. See mux(4) for more information.
streams-nuls
This kernel module contains the nuls STREAMS driver. This is a standard STREAMS module. See nuls(4) for more information.
streams-pipe
This kernel module contains the pipe STREAMS driver. This is a standard STREAMS driver. See pipe(4) for more information.
streams-log
This kernel module contains the log STREAMS driver. This is a standard STREAMS driver. See log(4) for more information.
streams-loop
This kernel module contains the loop STREAMS driver. This is a standard STREAMS driver, but is also used by the conformance and validation test suite. See loop(4) for more information.
streams-sfx
This kernel module contains the sfx STREAMS driver. This is a common character device driver for implementing STREAMS FIFOs. See sfx(4) for more information.
streams-spx
This kernel module contains the spx STREAMS driver. This is a common character device driver for implementing STREAMS pipes. See spx(4) for more information.
streams-bufmod
This kernel module contains the bufmod STREAMS module. The bufmod STREAMS module is a simple buffer module (a module that always defers to its service procedure and then passes any message along). This module is used for performance testing of the STREAMS package. See bufmod(4) for more information.
streams-nullmod
This kernel module contains the nullmod STREAMS module. The nullmod STREAMS module is a simple null module (a module that always passes messages to the next module in along the Stream). This module is used for performance testing of the STREAMS package and is also used by the conformance and validation test suite. See nullmod(4) for more information.
streams-pipemod
This kernel module contains the pipemod STREAMS module. This is a standard STREAMS module used with pipes. See pipemod(4) for more information.
streams-connld
This kernel module contains the connld STREAMS module. This is a standard STREAMS module. See connld(4) for more information.
streams-sc
This kernel module contains the sc STREAMS module. This is a common STREAMS Configuration module. See sc(4) for more information.
streams-testmod
This kernel module contains the testmod STREAMS module. This is a Linux Fast-STREAMS specific test module that is used for conformance and validation testing of STREAMS. See testmod(4) for more information.

Additional kernel modules are provided by add-on packages.

3.2 Drivers

The configuration of STREAMS drivers and modules is performed when compiling the Linux Fast-STREAMS subsystem. The STREAMS subsystem, core drivers and modules are part of every Linux Fast-STREAMS system.

The following lists the core drivers and modules, STREAMS kernel tunable parameters, and STREAMS configuration information:8

clone(4) (streams)
Clone device driver. This is a standard SVR 4.2 STREAMS driver. The clone(4) driver is a integral part of STREAMS and is used to create clone instances of a STREAMS driver.

See clone(4) for more information.

echo(4) (streams-echo)
Echo (loopback) device driver. This is a commonly implemented STREAMS driver. It is implemented by HP-UX® and OSF/1®. The echo(4) driver provides a simple FIFO-like device without full POSIX FIFO semantics. Its primary purpose is for the STREAMS Verification function, strvf(8), and the test-streams(8) validation test suite.

See echo(4) for more information.

fifo(4) (streams-fifo)
FIFO (Named Pipe) device driver. This is a standard SVR 4.2 STREAMS driver. The fifo(4) driver provides POSIX-compliant STREAMS-based FIFO device. Not all implementations of STREAMS provide STREAMS-based FIFOs: some implementations use the older SVR 3-style FIFOs that are not STREAMS-based. Linux Fast-STREAMS provides STREAMS-based FIFOs with the fifo(4) driver.

See fifo(4) for more information.

log(4) (streams-log)
STREAMS log driver. This is a standard SVR 4.2 STREAMS driver. The log(4) driver provides a STREAMS capable logger in addition to the BSD logger present in Linux. The log(4) driver provides additional support for STREAMS modules and drivers using the strlog(9) kernel level utility. Linux Fast-STREAMS also provides the strace(8), strerr(8) and strclean(8) administrative utility functions and startup scripts for controlling the log(4) driver.

See log(4) for more information.

loop(4) (streams-loop)
Loop device driver. This is a standard SVR 4.2 STREAMS driver. The loop driver is detailed in the UNIX System V Release 4 Programmer's Manual – STREAMS. The loop(4) driver provides capabilities used primarily for validation test programs (see test-streams(8)) as well as serving as an example driver.

See loop(4) for more information.

mux(4) (streams-mux)
Multiplexing driver. This is a standard SVR 4.2 STREAMS driver. The mux driver is detailed in the UNIX System V Release 4 Programmer's Manual – STREAMS. The mux(4) driver provides capabilities used primarily for validation test programs (see test-streams(8) as well as serving as an example multiplexing driver. This mux(4) driver also provides the minimux capabilities formerly present in LiS.

See mux(4) for more information.

nsdev(4) (streams-nsdev)
Named STREAMS device driver. This is a Linux Fast-STREAMS specific driver. The nsdev(4) driver is a clone(4)-like driver that permits the specification of major and minor device numbers using the device node name. It provides one of three mechanisms under Linux Fast-STREAMS that remove STREAMS driver dependency on statically allocated device numbers.

See nsdev(4) for more information.

nuls(4) (streams-nuls)
Null Stream driver. This is a standard SVR 4.2 STREAMS driver. The nuls(4) driver is usually called ‘null’. Linux has its own SVR3-style /dev/null driver, so it was renamed to ‘nuls’.

See nuls(4) for more information.

pipe(4) (streams-pipe)
STREAMS-based pipe driver. This is a standard SVR 4.2 STREAMS driver. However, pipe(4) is not normally implemented as a STREAMS driver, but is implemented as a system call. Linux Fast-STREAMS provides pipe(2s) system call emulation which invokes this driver internal to the kernel.

See pipe(4) for more information.

sad(4) (streams-sad)
STREAMS Administrative Driver. This is a standard SVR 4.2 STREAMS driver. The sad(4) driver is used by the autopush(8) utility to examine and specify the autopush lists for STREAMS drivers. Also, it is used to examine and verify the present of STREAMS modules or drivers in the system.

See sad(4) for more information.

sfx(4) (streams-sfx)
STREAMS FIFO device driver. This is commonly implemented STREAMS driver that is used to implement STREAMS FIFOs (Named Pipes) using a regular character device. The sfx(4) driver provides a character based device approach to creating FIFOs.

See sfx(4) for more information.

spx(4) (streams-spx)
STREAMS pipe device driver. This is commonly implemented STREAMS driver that is used to implement STREAMS pipes using a regular character device. The spx(4) driver provides a character based device approach to creating FIFOs and pipes. Only UnixWare® and AIX(4) document this device.

See spx(4) for more information.

Additional drivers are provided by add-on packages.

3.3 Modules

The configuration of STREAMS drivers and modules is performed when compiling the Linux Fast-STREAMS subsystem. The STREAMS subsystem, core drivers and modules are part of every Linux Fast-STREAMS system.

The following lists the core drivers and modules, STREAMS kernel tunable parameters, and STREAMS configuration information:9

pipemod(4) (streams-pipemod)
Pipe module. This is a standard SVR 4.2 STREAMS module. The pipemod(4) module can be pushed over a pipe end or FIFO before other modules are pushed (on either end) to reverse the sense of the M_FLUSH(9) message that traverse the pipe.

See pipemod(4) for more information.

connld(4) (streams-connld)
Connection Line Discipline module. This is a standard SVR 4.2 STREAMS module. The connld(4) module can be pushed over a pipe end that has been attached to a file system file using fattach(3) and will then create a new pipe instance on each open(2s) of the attached file and pass the new remove file pointer to the remove end using M_PASSFP(9) to be received with I_RECVFD(7). This allows servers to be created that use pipe(4)s for communication.

See connld(4) for more information.

sc(4) (streams-sc)
STREAMS Configuration module. This is a commonly implemented STREAMS module. It is implemented by HP-UX and AIX, and perhaps other Mentat-derived STREAMS implementations. The sc(4) modules provides the ability to access STREAMS driver information by name rather than major device number. It also provides access to the module_info(9) and module_stat(9) structure information for the named STREAMS module or driver, not accessible using the sad(4) driver. The sc(4) module is used by the scls(8) utility.

See sc(4) for more information.

bufmod(4) (streams-bufmod)
Buffer module. This is a standard SVR 4.2 STREAMS module described in the UNIX System V Release 4 Programmer's Manual – STREAMS. The bufmod(4) module also has Linux Fast-STREAMS specific extensions. The bufmod(4) module is used by the perftest(8) performance test program to test the effect of additional levels of service procedure pushed over a Stream. The module also serves as an example of a STREAMS module using service procedures.

See bufmod(4) for more information.

nullmod(4) (streams-nullmod)
Null module. This is a standard SVR 4.2 STREAMS module described in the UNIX System V Release 4 Programmer's Manual – STREAMS. The nullmod(4) module also has Linux Fast-STREAMS specific extensions. The nullmod(4) module is used by the perftest(8) performance test program to test the effect of additional levels of put procedure pushed over a Stream. The module also serves as an example of a STREAMS module not using service procedures.

See nullmod(4) for more information.

testmod(4) (streams-testmod)
Test module. This is a Linux Fast-STREAMS specific STREAMS module. The primary purpose of the testmod(4) modules is to provide the test-streams(8) validation test program with the capability to pass specific M_ERROR(9) and M_HANGUP(9) messages to the Stream head for POSIX validation testing. It also serves as an example of how a STREAMS module can properly process M_IOCTL(9) and related messages.

See testmod(4) for more information.

Additional modules are provided by add-on packages.

3.4 Libraries

During the installation process of Linux Fast-STREAMS a subroutine library is built and installed on your system. For 64-bit systems that support 32-bit compatibility, two versions of each library are built and installed: one 64-bit native library and one 32-bit compatibility library. 64-bit native libraries are installed to the /usr/lib64 subdirectory. 32-bit native and 32-bit compatibility libraries are installed to the /usr/lib subdirectory.

libstreams.so.0.0.1
libstreams.so.0
libstreams.so
Provides a shared object library for use by STREAMS applications programs.
libstreams.a
Provides a static library for use by STREAMS applications programs.
libstreams.la
Provides the libtool definitions for the library.

In addition to the libstreams library, Linux Fast-STREAMS also installs compatibility libraries for LiS. These compatibility libraries permit applications previously linked with LiS shared libraries to function with Linux Fast-STREAMS without recompiling or relinking.

libLiS.so.0.0.1
libLiS.so.0
libLiS.so
Provides a shared object library for use by legacy LiS applications programs.
libLiS.a
Provides a static library for use by legacy LiS applications programs.
libLiS.la
Provides the libtool definitions for the library.
libpLiS.so.0.0.1
libpLiS.so.0
libpLiS.so
Provides a shared object library for use by legacy LiS applications programs.
libpLiS.a
Provides a static library for use by legacy LiS applications programs.
libpLiS.la
Provides the libtool definitions for the library.

3.4.1 libstreams Library Routines

The following routines are present in the libstreams libraries. The routines in these libraries are standard STREAMS interface system calls documented in the System V Release 4.2 Programmer's Manual – STREAMS. Refer to the associated manual pages for detailed information on these routines.

fattach(2)
Name a STREAMS special file.
fdetach(2)
Unname a STREAMS special file.
getmsg(2)
Get next message off of a Stream.
getpmsg(2s)
Get next message off of a Stream.
isastream(2)
Test for a STREAMS special file.
pipe(2s)
Create a STREAMS pipe.
putmsg(2)
Put a message to a STREAMS character device.
putpmsg(2s)
Put a band message to a STREAMS character device.
pstrlog(3)
Print a STREAMS log buffer.
strlog(3)
Print a STREAMS log buffer.
vstrlog(3)
Print a STREAMS log buffer.

3.4.2 libLiS Library Routines

The following routines are present in the libLiS libraries. The routines are identical to the routines present in the libstreams library and are provided in the libLiS library for compatibility with existing applications linked against libLiS.

fattach(2)
Name a STREAMS special file.
fdetach(2)
Unname a STREAMS special file.
getmsg(2)
Get next message off of a Stream.
getpmsg(2s)
Get next message off of a Stream.
isastream(2)
Test for a STREAMS special file.
pipe(2s)
Create a STREAMS pipe.
putmsg(2)
Put a message to a STREAMS character device.
putpmsg(2s)
Put a band message to a STREAMS character device.

3.4.3 libpLiS Library Routines

The following routines are present in the libpLiS libraries. The libpLiS library is the same as the libLiS and libstreams libraries but omits the pipe(2s) subroutine. The purpose of the libpLiS library was to permit it to be used as a library preload without affecting the pipe(2s) function used by existing programs linked against libc.

fattach(2)
Name a STREAMS special file.
fdetach(2)
Unname a STREAMS special file.
getmsg(2)
Get next message off of a Stream.
getpmsg(2s)
Get next message off of a Stream.
isastream(2)
Test for a STREAMS special file.
putmsg(2)
Put a message to a STREAMS character device.
putpmsg(2s)
Put a band message to a STREAMS character device.

3.4.4 Using the Library

To use one of the Linux Fast-STREAMS libraries you can include the file sys/stropts.h in you application program source code. On you compiler command line, add the option ‘-I/usr/include/streams’ to include the version of sys/stropts.h that is distributed with Linux Fast-STREAMS.

When linking our program, or performing a final gcc to build your executable, include one of the following options on your command line:

/usr/lib/libstreams.a
-lstreams -static
Link against the static version of the library.
-lstreams
Link against the shared object version of the library.
/usr/lib/libstreams.la
Use with libtool to link additional convenience libraries against the shared or static versions of the library.

Failure to link the executable runtime path for libstreams will result in linker-loader warnings that the functions getpmsg(2s) or putpmsg(2s) are not implemented and will always fail.10.

See also Development for more information.

3.5 Utilities

3.5.1 Init Scripts

Following are System V Init Scripts that are installed by the package:

specfs(8) (/etc/init.d/specfs)
specfs.sh(8) (/etc/init.d/specfs.sh)
System V Init Script for the STREAMS Special Shadow Filesystem. The specfs(8) init script provides the ability to initialize, configure and mount the STREAMS Special Shadow Filesystem, specfs(5). The specfs(8) script provides the RedHat-style init script, whereas the specfs.sh(8) script provides the Debian-style init script.

See specfs(8) for more information.

streams(8) (/etc/init.d/streams)
streams.sh(8) (/etc/init.d/streams.sh)
System V Init Script for the STREAMS Subsystem. The streams(8) init script provides the ability to initialize, configure and mount the STREAMS subsystem, STREAMS(9). The streams(8) script provides the RedHat-style init script, whereas the streams.sh(8) script provides the Debian-style init script.

See streams(8) for more information.

3.5.2 User Utilities

Following are user utilities for manipulating Streams:

strchg(1) (/usr/bin/strchg)
Change Stream configuration. strchg(1) is a standard SVR 4.2 STREAMS user utility.

strchg(1) is a C-language user program that can be used to alter the configuration of the Stream associated with the caller's standard input. The strchg(1) command pushes modules on the Stream, pops modules off of the Stream, or both. Only the superuser or owner of the STREAMS device can alter the configuration of that Stream. If another user attempts to alter the configuration, the strconf(1) command will fail.

strchg(1) is useful from the shell and, when standard input is redirected from an open file descriptor to the command, can be used to push and pop modules from arbitrary Streams, not just those associated with STREAMS-based terminal devices.

See strchg(1) for more information.

strconf(1) (/usr/bin/strconf)
Query Stream configuration. strconf(1) is a standard SVR 4.2 STREAMS user utility.

strconf(1) is a C-language user program that can be used to query the configuration of a Stream. When use without any options, it prints a list of the modules in the Stream associated with the standard input, as well as the topmost driver. The list is printed with one name per line, where the first name printed is the topmost module on the Stream and the last item printed is the name of the topmost driver associated with the Stream.

strconf(1) is useful from the shell and, when standard input is redirected from an open file descriptor to the command, can be used to query arbitrary Streams, not just the associated with STREAMS-based terminal devices.

See strconf(1) for more information.

strreset(1) (/usr/bin/strreset)
Reset a Stream. strreset(1) is a standard SVR 4.2 STREAMS user utility.

strreset(1)is a C-language user program that resets an open Stream by generating an M_FLUSH(9) message to the Stream head. It is used mainly to reset blocked Streams. Wehn it is impossible to reopen the Stream, issue an I_FLUSH or equivalent command. This situation may happen with a process sleeping in a module's close routine, when signals can not be sent to the process (a zombie process exiting, for example).

See strreset(1) for more information.

3.5.3 Administrative Utilities

Following are administrative utilities for manipulating and examining the STREAMS subsystem:

autopush(8) (/usr/sbin/autopush)
Control the autopush module list for a STREAMS device. autopush(8) is a standard SVR 4.2 STREAMS administrative utility.

autopush(8) is a C-language program that can be used to manipulate and examine which STREAMS modules are automatically pushed over a device when it is opened. It is also possible to restrict the ability to push further modules on the Stream without proper privilege. The autopush(8) utility provides a user program interface to the STREAMS Administrative Driver (sad(4)).

See autopush(8) for more information.

fattach(8) (/usr/sbin/fattach)
Name a STREAMS file. fattach(8) is an LiS utility. Although OSF/1 documentation mentions an fattach manual page in section 8, one does not exist.

fattach(8) opens a pipe(4) and attaches one end of the pipe to a file using fattach(3), and optionally pushes the connld(4) module on the side of the pipe being attached to the file. The other end of the pipe remains available for use by the shell program invoking this command.

fattach(8) provides a easy way for shell programs to use STREAMS-based pipes and to use the facilities of the connld(4) module.

See fattach(8) for more information.

fdetach(8) (/usr/sbin/fdetach)
Unlink a named STREAMS file.

fdetach(8) is a standard SVR 4.2 STREAMS administrative utility.

fdetach(8) is a C-language program that detaches or disassociates a file descriptor for an open STREAMS device or pipe from its filename in the file system.

See fdetach(8) for more information.

insf(8) (/usr/sbin/insf)
Install special files. insf(8) is the HP-UX way to install special (device) files. This program is not even partially implemented in Linux Fast-STREAMS. Use streams_mknod(8) and friends instead.

See insf(8) for more information.

scls(8) (/usr/sbin/scls)
List STREAMS configuration. scls(8) is a rather useful AIX administrative utility that is also implemented by Linux Fast-STREAMS.

scls(8) is a C-language program that can be used to list module and driver names as well as information and statistics associated with those modules or drivers. The scls(8) utility provides a user program interface to the STREAMS Configuration module (sc(4)).

See scls(8) for more information.

strace(8) (/usr/sbin/strace)
Write STREAMS event trace messages to the standard output. strace(8) is a standard SVR 4.2 STREAMS administrative utility.

The strace(8) C-language program receives trace event messages from the STREAMS log driver (log(4)) and writes these messages to the standard output. When run as a daemon, strace(8) appends these messages to a log file.

Messages that appear in the trace log are intended to report debugging information that assists with troubleshooting a running STREAMS module or driver.

See strace(8) for more information.

strclean(8) (/usr/sbin/strclean)
Clean up after the STREAMS error logger. strclean(8) is a standard SVR 4.2 STREAMS administrative utility.

The strclean(8) utility is a bash script that can be used to delete aged log files generated by the STREAMS error logger, strerr(8).

See strclean(8) for more information.

streams_mknod(8) (/usr/sbin/streams_mknod)
Make special device nodes for STREAMS. streams_mknod(8) is a Linux Fast-STREAMS specific administrative utility.

The streams_mknod(8) C-language program can be used to make (or remove) the special device nodes under the /dev directory required by streams-0.9.2.4 package modules and drivers. streams_mknod(8) in invoked by the System V startup script, /etc/init.d/streams.

See streams_mknod(8) for more information.

strerr(8) (/usr/sbin/strerr)
Receive error log messages from the STREAMS log(4) driver. strerr(8) is a standard SVR 4.2 STREAMS administrative utility.

The strerr(8) utility is a C-language program, run as a daemon, that receives error log messages from the STREAMS log driver (log(4)) and writes these message to a log file. By default, strerr(8) logs all STREAM error messages from all drivers and modules.

Messages that appear in the error log are intended to report exceptional conditions that require the attention of the person who administers your system.

See strerr(8) for more information.

strinfo(8) (/usr/sbin/strinfo)
List Stream information. strinfo(8) is a rather useful AIX administrative utility that is also implemented by Linux Fast-STREAMS.

The strinfo(8) C-language program can be used to list Stream instance information as well as information and statistics on a module or driver basis. The scls(8) utility provides a user program interface to the STREAMS Configuration module (sc(4)).

This program is not even partially implemented in Linux Fast-STREAMS yet. User proc(5) file system and the /proc/streams directory instead. Also, see scls(8) for driver and module specific information.

See strinfo(8) for more information.

strload(8) (/usr/sbin/strload)
Loads the STREAMS subsystem. strload(8) is a useful AIX administrative utility that is also implemented by Linux Fast-STREAMS.

The strload(8) bash script can be used to load STREAMS modules and drivers individually or from a configuration file.

See strload(8) for more information.

strsetup(8) (/usr/sbin/strsetup)
Bash script.

See strsetup(8) for more information.

strvf(8) (/usr/sbin/strvf)
C-language program.

See strvf(8) for more information.

3.5.4 Performance Test Programs

Following are performance test programs:

perftest(8) (/usr/sbin/perftest)
C-language program.

See perftest(8) for more information.

perftestn(8) (/usr/sbin/perftestn)
C-language program.

See perftestn(8) for more information.

3.5.5 Conformance Test Programs

Following and conformance and validation testing programs:

test-clone(8) (/usr/libexec/streams/test-clone)
The test-clone(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the clone(4) STREAMS driver.

See test-clone(8) for more information.

test-connld(8) (/usr/libexec/streams/test-connld)
The test-connld(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the connld(4) STREAMS driver.

See test-connld(8) for more information.

test-echo(8) (/usr/libexec/streams/test-echo)
The test-echo(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the echo(4) STREAMS driver.

See test-echo(8) for more information.

test-fifo(8) (/usr/libexec/streams/test-fifo)
The test-fifo(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the fifo(4) STREAMS driver.

See test-fifo(8) for more information.

test-log(8) (/usr/libexec/streams/test-log)
The test-log(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the log(4) STREAMS driver.

See test-log(8) for more information.

test-loop(8) (/usr/libexec/streams/test-loop)
The test-loop(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the loop(4) STREAMS driver.

See test-loop(8) for more information.

test-mux(8) (/usr/libexec/streams/test-mux)
The test-mux(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the mux(4) STREAMS driver.

See test-mux(8) for more information.

test-nsdev(8) (/usr/libexec/streams/test-nsdev)
The test-nsdev(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the nsdev(4) STREAMS driver.

See test-nsdev(8) for more information.

test-nuls(8) (/usr/libexec/streams/test-nuls)
The test-nuls(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the nuls(4) STREAMS driver.

See test-nuls(8) for more information.

test-pipe(8) (/usr/libexec/streams/test-pipe)
The test-pipe(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the pipe(4) STREAMS driver.

See test-pipe(8) for more information.

test-pipemod(8) (/usr/libexec/streams/test-pipemod)
The test-pipemod(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the pipemod(4) STREAMS driver.

See test-pipemod(8) for more information.

test-sad(8) (/usr/libexec/streams/test-sad)
The test-sad(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the sad(4) STREAMS driver.

See test-sad(8) for more information.

test-sc(8) (/usr/libexec/streams/test-sc)
The test-sc(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the sc(4) STREAMS driver.

See test-sc(8) for more information.

test-streams(8) (/usr/libexec/streams/test-streams)
The test-streams(8) C-language program is a conformance and validation test program, in the OpenSS7 Project style, for the STREAMS(9) subsystem and primarily the sth(4) Stream head.

See test-streams(8) for more information.

For the proper way to execute these validation test programs in a conformance and validation test suite, see Running Test Suites.

4 Development

For development using the streams package, See About This Manual.

4.1 Header Files

Header files are installed, typically, in the /usr/include/streams subdirectory. To use the header files from the package, ‘-I/usr/include/streams’ must be included in the gcc command line as a compile option. This is true regardless of whether user space or kernel space programs are being compiled.

In general, ‘-I’ include directives on the gcc command line should be ordered in the reverse order of the dependencies between packages. So, for example, if the include files from all add-on packages are required, the order of these directives would be: ‘-I/usr/include/strss7 -I/usr/include/strsctp -I/usr/include/strinet -I/usr/include/strxnet -I/usr/include/strxns -I/usr/include/strcompat -I/usr/include/streams’.

Following are the user visible header files provided by the streams-0.9.2.4 package in directory /usr/include/streams:

strlog.h
This is the primary header file for the strlog(4) driver. It is normally only included by user space programs when interacting with the log(4) driver. See log(4) for more information.
stropts.h
This is the primary user header file for the Stream head. It is normally only included by user space programs when interacting with the Stream head. See sth(4) for more information.
log.h
This is the primary header file for the log(4) driver. It is normally only included by user space programs when interacting with the log(4) driver. See log(4) for more information.
loop.h
This is the primary header file for the loop(4) driver. It is normally only included by user space programs when interacting with the loop(4) driver. See loop(4) for more information.
sad.h
This is the primary header file for the sad(4) driver. It is normally only included by user space programs when interacting with the sad(4) driver. See sad(4) for more information.
sys/cmn_err.h
This is the system specific kernel header file for the cmn_err(9) utility.
sys/ddi.h
This is the system specific kernel header file for various STREAMS DDI(9) utilities. It is normal only included by kernel space STREAMS modules and drivers. See DDI(9) for more information.
sys/debug.h
This is the system specific kernel header file for kernel debugging macros. It is normal only included by kernel space STREAMS modules and drivers.
sys/dki.h
This is the system specific kernel header file for various STREAMS DKI(9) utilities. It is normal only included by kernel space STREAMS modules and drivers. See DKI(9) for more information.
sys/kmem.h
This is the system specific kernel header file for kmem_alloc(9) and related utilities. It is normal only included by kernel space STREAMS modules and drivers. See kmem_alloc(9) for more information.
sys/strconf.h
This is the system specific kernel header file for STREAMS driver and module configuration. It is normal only included by kernel space STREAMS modules and drivers.
sys/strdebug.h
This is the system specific kernel header file for STREAMS driver and module debugging macros. It is normal only included by kernel space STREAMS modules and drivers.
sys/stream.h
This is the system specific kernel header file for STREAMS drivers and modules. It is normal only included by kernel space STREAMS modules and drivers. See STREAMS(9) for more information.
sys/strlog.h
This is the system specific header file for the strlog(4) and strlog(9) facilities. It is normally only included by kernel space programs when interacting with the log(4) driver. See log(4) for more information.
sys/stropts.h
This is the system specific user header file for the Stream head. It is normally only included by user space programs when interacting with the Stream head. See sth(4) for more information.
sys/stropts32.h
This is the system specific user 32/64-bit header file for the Stream head. It is normally only included by user space programs when interacting with the Stream head. See sth(4) for more information.
sys/strsubr.h
This is the system specific kernel header file for STREAMS private definitions. It is normal only included by kernel space STREAMS modules and drivers. See STREAMS(9) for more information.
sys/log.h
This is the system specific header file for the log(4) driver. It is normally only included by kernel space programs when interacting with the log(4) driver. See log(4) for more information.
sys/loop.h
This is the system specific header file for the loop(4) driver. It is normally only included by kernel space programs when interacting with the loop(4) driver. See loop(4) for more information.
sys/sad.h
This is the system specific header file for the sad(4) driver. It is normally only included by kernel space programs when interacting with the sad(4) driver. See sad(4) for more information.
sys/sc.h
This is the system specific header file for the sc(4) module. It is normally only included by user or kernel space programs when interacting with the sc(4) driver. See sc(4) for more information.
sys/testmod.h
This is the system specific header file for the testmod(4) module. It is normally only included by user or kernel space programs when interacting with the testmod(4) driver. See testmod(4) for more information.

4.1.1 User Space Programs

Typical include files for interacting with STREAMS from user space include the stropts.h header file. Additional header files for interacting with specific drivers or modules may also be required.

4.1.2 Kernel Space Drivers and Modules

Typical include files for writing STREAMS modules and drivers for kernel space include the sys/cmn_err.h, sys/kmem.h, sys/dki.h, sys/stream.h, sys/ddi.h, and sys/strconf.h header files. Additional header files for interacting with specific drivers or modules may also be required.

4.2 Libraries

Shared or static versions of the libstreams library must be linked when using the streams-0.9.2.4 package. This library must either be specified on the gcc command line as a shared library (e.g. ‘-lstreams’) or as a static library (e.g. ‘/usr/lib/libstreams.a’).

If the shared library is linked, include the following options on the gcc command line:

-lstreams
Link to the /usr/lib/libstreams.so shared library.

If the static library is linked, include the following options on the gcc command line:

/usr/lib/libstreams.a
Link to the /usr/lib/libstreams.a static library.

4.3 Kernel Modules

Developing STREAMS kernel modules is similar to user space programs with regard to header files. /usr/include/streams should be placed as an include directory to search in the gcc command line. The rules for compiling Linux kernel modules should be followed. In particular, several important intricacies should be considered:

  • The gcc compiler used to compile the kernel modules must be the same version of compiler that was used to compile the kernel.
  • The gcc command line must have the same compile flags that were used to compile the kernel.
  • The gcc command line must define several important kernel defines including ‘-DLINUX’, ‘-D__KERNEL__’, as well as the base name of the module.
  • The gcc command line must include several important include files directly on the command line such as ‘--include /lib/modules/2.4.20-28.7/build/include/linux/autoconf.h’ and maybe even ‘--include /lib/modules/2.4.20-28.7/build/include/linux/modversions.h’.11

4.4 Manual Pages

The streams-0.9.2.4 package installs a number of manual pages in the /usr/share/man directory as follows:

The following manual pages are installed in Section 1 of the manual (in the subdirectory /usr/share/man/man1):

strchg(1)change Stream configuration.
strconf(1)query Stream configuration.
strreset(1)reset a Stream.

The following manual pages are installed in Section 2 of the manual (in the subdirectory /usr/share/man/man2):

fattach(2)name a STREAMS special file.
fdetach(2)unname a STREAMS special file.
getmsg(2)get next message off a Stream.
getpmsg(2s)get next message off a Stream.
isastream(2)test for a STREAMS special file.
pipe(2s)create a STREAMS pipe.
poll(2s)wait for an event on a STREAMS file descriptor.
putmsg(2)put a message to a STREAMS character device.
putpmsg(2s)put a band message to a STREAMS character device.
read(2s)read from a file descriptor.
readv(2s)read or write a vector.
write(2s)write to a file descriptor.
writev(2s)read or write a vector.

The following manual pages are installed in Section 3 of the manual (in the subdirectory /usr/share/man/man3):

streams(3)STREAMS system call library.
libstreams(3)STREAMS system call library.
LiS(3)STREAMS system call library.
pLiS(3)STREAMS system call library.
libLiS(3)STREAMS system call library.
libpLiS(3)STREAMS system call library.
fattach(3)name a STREAMS special file.
fdetach(3)unname a STREAMS special file.
isastream(3)test for a STREAMS special file.
pipe(3)create a STREAMS pipe.
pstrlog(3)print a STREAMS log buffer.
s_pipe(3)create a STREAMS pipe.
strlog(3)print a STREAMS log buffer.
vstrlog(3)print a STREAMS log buffer.

The following manual pages are installed in Section 4 of the manual (in the subdirectory /usr/share/man/man4):

bufmod(4)STREAMS buffering null module.
clone(4)the STREAMS clone driver.
connld(4)STREAMS connection line discipline module.
conslog(4)STREAMS log device.
echo(4)echo STREAMS device.
fifo(4s)STREAMS-based FIFO device.
log(4)STREAMS log device.
loop(4)STREAMS loop-around pseudo-device driver.
loop_clone(4)STREAMS loop-around pseudo-device driver.
mux(4)STREAMS multiplexing pseudo-device driver.
nsdev(4)named STREAMS device.
nullmod(4)STREAMS null module.
nuls(4)null STREAMS device.
pipe(4)STREAMS bi-directional pipe device.
pipemod(4)STREAMS-based pipe module.
s_fifo(4)STREAMS-based FIFO device.
sad(4)STREAMS Administrative Driver.
sc(4)STREAMS Configuration module.
sfx(4)STREAMS-based FIFO device.
sloop(4)STREAMS loop-around pseudo-device driver.
spx(4)STREAMS bi-directional pipe device.
sth(4)STREAMS Stream head module.
strlog(4)STREAMS log device.
testmod(4)STREAMS test module.

The following manual pages are installed in Section 5 of the manual (in the subdirectory /usr/share/man/man5):

autopush(5)control the autopush module list for a STREAMS device.
specfs(5)STREAMS special device shadow file system.
strapush(5)STREAMS autopush structure.
strioctl(5)STREAMS I/O control data structure.
strsetup.conf(5)configuration file for STREAMS drivers.

The following manual pages are installed in Section 7 of the manual (in the subdirectory /usr/share/man/man7):

streamio(7)STREAMS ioctl commands.
I_ANCHOR(7)STREAMS anchor input-output control.
I_ATMARK(7)check if a STREAMS message is marked.
I_CANPUT(7)check if a STREAMS band is writable.
I_CKBAND(7)check if a STREAMS band is readable.
I_EGETSIG(7)get enhanced STREAMS SIGPOLL events.
I_ESETSIG(7)set enhanced STREAMS SIGPOLL events.
I_FATTACH(7)emulate fattach(2) system call.
I_FDETACH(7)emulate fdetach(2) system call.
I_FDINSERT(7)insert a Stream identifier into a STREAMS message and send it downstream.
I_FIND(7)find a STREAMS module on a Stream.
I_FLUSH(7)flush messages from a STREAMS special file.
I_FLUSHBAND(7)flush messages for a band from a STREAMS special file.
I_GERROPT(7)get error options for a STREAMS file.
I_GETBAND(7)get band number of a message on a Stream.
I_GETCLTIME(7)get close time for a STREAMS file.
I_GETPMSG(7)STREAMS getpmsg(2s) system call emulation.
I_GETSIG(7)get SIGPOLL events.
I_GRDOPT(7)get STREAMS read options.
I_GWROPT(7)get STREAMS write options.
I_ISASTREAM(7)emulate isastream(2) system call.
I_LINK(7)link a Stream beneath a STREAMS multiplexing driver.
I_LIST(7)list STREAMS module names on a Stream.
I_LOOK(7)look at topmost STREAMS module on a Stream.
I_NREAD(7)number of unread bytes on a Stream.
I_PEEK(7)peek at STREAMS message on read queue.
I_PIPE(7)obtain a STREAMS based pipe.
I_PLINK(7)persistently link a Stream beneath a STREAMS multiplexing driver.
I_POP(7)pop a STREAMS module from a Stream.
I_PUNLINK(7)unlink a STREAMS persistent link.
I_PUSH(7)push a STREAMS module on a Stream.
I_PUTPMSG(7)STREAMS putpmsg(2s) system call emulation.
I_RECVFD(7)receive a file descriptor on a Stream.
I_SENDFD(7)send a file descriptor on a Stream.
I_SERROPT(7)set error options for a STREAMS file.
I_SETCLTIME(7)set close time for a STREAMS file.
I_SETSIG(7)set SIGPOLL events.
I_SRDOPT(7)set STREAMS read options.
I_STR(7)STREAMS intput-output control.
I_SWROPT(7)set STREAMS write options.
I_UNLINK(7)unlink a Stream from a STREAMS multiplexing driver.

The following manual pages are installed in Section 8 of the manual (in the subdirectory /usr/share/man/man8):

autopush(8)control the autopush module list for a STREAMS device.
fattach(8)name a STREAMS file.
fdetach(8)unname a STREAMS file.
insf(8)install special device files.
perftest(8)STREAMS benchmark performance tests on a pipe.
perftestn(8)STREAMS benchmark performance tests on a pipe.
scls(8)produce a list of STREAMS module and driver names.
specfs(8)System V Init Script for the STREAMS Shadow Special Filesystem.
specfs.sh(8)System V Init Script for the STREAMS Shadow Special Filesystem.
strace(8)write STREAMS event trace messages to the standard output.
strclean(8)clean up the STREAMS error logger.
streams(8)System V Init Script for the STREAMS subsystem.
streams_mknod(8)create or remove STREAMS device nodes.
streams.sh(8)System V Init Script for the STREAMS subsystem.
strerr(8)receive error log messages from the STREAMS log(4) driver.
strinfo(8)display information about STREAMS devices.
strload(8)load the STREAMS subsystem.
strsetup(8)STREAMS setup command.
strvf(8)STREAMS verification tool.
test-clone(8)a test suite executable for the clone(4) STREAMS driver.
test-connld(8)a test suite executable for the connld(4) STREAMS module.
test-echo(8)a test suite executable for the echo(4) STREAMS driver.
test-fifo(8)a test suite executable for the fifo(4) STREAMS driver.
test-log(8)a test suite executable for the log(4) STREAMS driver.
test-loop(8)a test suite executable for the loop(4) STREAMS driver.
test-mux(8)a test suite executable for the mux(4) STREAMS driver.
test-nsdev(8)a test suite executable for the nsdev(4) STREAMS driver.
test-nuls(8)a test suite executable for the nuls(4) STREAMS driver.
test-pipe(8)a test suite executable for the pipe(4) STREAMS driver.
test-pipemod(8)a test suite executable for the pipemod(4) STREAMS module.
test-sad(8)a test suite executable for the sad(4) STREAMS driver.
test-sc(8)a test suite executable for the sc(4) STREAMS module.
test-streams(8)a test suite executable for STREAMS.

The following manual pages are installed in Section 9 of the manual (in the subdirectory /usr/share/man/man9):

Intro(9)introduction to STREAMS kernel functions.
STREAMS(9)introduction to STREAMS kernel functions.
SPG(9)Linux Fast-STREAMS Programmers Guide.
DDI(9)Device Driver interface/Driver Kernel Interface.
LfS(9)introduction to STREAMS kernel functions.
mp-streams(9)multi-processor STREAMS executive.
M_BACKDONE(9)STREAMS backwash done direct I/O message.
M_BACKWASH(9)STREAMS backwash direct I/O message.
M_BREAK(9)STREAMS break message.
M_COPYIN(9)STREAMS copyin message.
M_COPYOUT(9)STREAMS copyout message.
M_CTL(9)STREAMS control message.
M_DATA(9)STREAMS data message.
M_DELAY(9)STREAMS delay message.
M_DONTPLAY(9)STREAMS don't play direct I/O message.
M_ERROR(9)STREAMS error message.
M_EVENT(9)STREAMS event message.
M_FLUSH(9)STREAMS flush message.
M_HANGUP(9)STREAMS hangup message.
M_HPDATA(9)STREAMS high priority data message.
M_IOCACK(9)STREAMS IO control acknowledgement message.
M_IOCDATA(9)STREAMS IO control data message.
M_IOCNAK(9)STREAMS IO control negative acknowledgement message.
M_IOCTL(9)STREAMS IO control message.
M_LETSPLAY(9)STREAMS let's plan direct I/O message.
M_NOTIFY(9)STREAMS notify message.
M_PASSFP(9)STREAMS pass file pointer message.
M_PCCTL(9)STREAMS priority control message.
M_PCEVENT(9)STREAMS priority event message.
M_PCPROTO(9)STREAMS priority protocol message.
M_PCRSE(9)STREAMS priority reserved message.
M_PCSETOPTS(9)STREAMS priority set options message.
M_PCSIG(9)STREAMS priority signal message.
M_PROTO(9)STREAMS protocol message.
M_READ(9)STREAMS read message.
M_RSE(9)STREAMS reserved message.
M_SETOPTS(9)STREAMS set options message.
M_SIG(9)STREAMS signal message.
M_START(9)STREAMS start message.
M_STARTI(9)STREAMS start input message.
M_STOP(9)STREAMS stop message.
M_STOPI(9)STREAMS stop input message.
M_TRAIL(9)STREAMS trail message.
M_UNHANGUP(9)STREAMS unhangup message.
OTHERQ(9)return other queue of a STREAMS queue pair.
QNORM(9)STREAMS data block structure.
QPCTL(9)STREAMS data block structure.
RD(9)return the read queue of a STREAMS queue pair.
SAMESTR(9)test for a STREAMS pipe or FIFO.
WR(9)return the write queue of a STREAMS queue pair.
adjmsg(9)trim bytes from the front or back of a STREAMS message.
allocb(9)allocate a STREAMS message and data block.
alloclk(9)allocate or free a STREAMS link block.
allocq(9)allocate a STREAMS queue pair.
allocstr(9)allocate a STREAMS Stream head.
appq(9)append one STREAMS message after another.
apush_get(9)get the autopush list associated with a STREAMS driver.
apush_set(9)set the autopush list associated with a STREAMS driver.
apush_vml(9)verify a STREAMS module list.
autopush(9)perform autopush operations on a newly opened Stream.
autopush_add(9)add an autopush list entry for a given STREAMS device number.
autopush_del(9)delete an autopush list entry for a given STREAMS device number.
autopush_find(9)find an autopush list entry for a given STREAMS device number.
autopush_search(9)find an autopush list entry for a given STREAMS device name and number.
autopush_vml(9)verify a STREAMS module list.
backq(9)find the upstream or downstream queue.
bcanget(9)test for message arrival on a band on a Stream.
bcangetany(9)check whether messages are in any (non-zero) band.
bcanput(9)test flow control on a STREAMS message queue.
bcanputany(9)check if a message can be put to any (non-zero) band on a queue.
bcanputnext(9)test flow control on the next STREAMS message queue.
bcanputnextany(9)check if a message can be put to any (non-zero) band on the next queue.
bcid_t(9)install a buffer callback.
bcmp(9)compare byte strings.
bcopy(9)copy byte strings.
bufcall(9)install a buffer callback.
bufcall_id_t(9)install a buffer callback.
bzero(9)zero a byte string.
canenable(9)test whether a STREAMS message queue can be scheduled.
canget(9)test for message arrival on a Stream.
canput(9)test flow control on a STREAMS message queue.
canputnext(9)test flow control on the next STREAMS message queue.
cdev_count(9)character device switch table helper functions.
cdev_find(9)character device switch table helper functions.
cdev_match(9)character device switch table helper functions.
cdev_minor(9)character device switch table helper functions.
cdev_str(9)character device switch table helper functions.
cdevsw(9)the SVR 4 character device switch table structure.
cdevsw_list(9)the SVR 4 character device switch table structure.
cdevsw_lock(9)the SVR 4 character device switch table structure.
cdrv_get(9)the SVR 4 character device switch table structure.
cdrv_put(9)the SVR 4 character device switch table structure.
cmaj_add(9)major/minor character device node helper functions.
cmaj_del(9)major/minor character device node helper functions.
cmaj_get(9)major/minor character device node helper functions.
cmin_add(9)major/minor character device node helper functions.
cmin_count(9)major/minor character device node helper functions.
cmin_del(9)major/minor character device node helper functions.
cmin_find(9)major/minor character device node helper functions.
cmin_get(9)major/minor character device node helper functions.
cmin_ini(9)major/minor character device node helper functions.
cmin_rel(9)major/minor character device node helper functions.
cmn_err(9)print a kernel command error.
copyb(9)copy a STREAMS message block.
copyin(9)copy user data in from user space to kernel space.
copymsg(9)copy a STREAMS message.
copyout(9)copy user data in from kernel space to user space.
copyreq(9)STREAMS copy request block structure.
copyresp(9)STREAMS copy response block structure.
cred_t(9)credentials structure.
ctlmsg(9)test a STREAMS message type for control.
datab(9)STREAMS data block structure.
datamsg(9)test a STREAMS message type for data.
dblk_t(9)STREAMS data block structure.
delay(9)postpone the calling process for a number of clock ticks.
dev_t(9)STREAMS device type.
devnode(9)STREAMS character device node structure.
do_fattach(9)implement the fattach(2) system call.
do_fdetach(9)implement the fdetach(2) system call.
do_spipe(9)implement the pipe(2s) system call.
drv_getparm(9)driver retrieve kernel parameter.
drv_hztomsec(9)convert kernel tick time between microseconds or milliseconds.
drv_hztousec(9)convert kernel tick time between microseconds or milliseconds.
drv_msectohz(9)convert kernel tick time between microseconds or milliseconds.
drv_priv(9)check if current process is privileged.
drv_usectohz(9)convert kernel tick time between microseconds or milliseconds.
drv_usecwait(9)delay for a number of microseconds.
dupb(9)duplicate a STREAMS message block.
dupmsg(9)duplicate a STREAMS message.
enableok(9)allow a STREAMS message queue to be scheduled.
enableq(9)schedule a STREAMS message queue service procedure.
esballoc(9)allocate a STREAMS message and data block with caller supplied data buffer.
esbbcall(9)install a buffer callback for an extended STREAMS message block.
flushband(9)flushes a band of STREAMS messages from a queue.
flushq(9)flush messages from a STERAMS message queue.
fmod_add(9)file module switch table helper functions.
fmod_count(9)file module switch table helper functions.
fmod_del(9)file module switch table helper functions.
fmod_find(9)file module switch table helper functions.
fmod_get(9)file module switch table helper functions.
fmod_put(9)file module switch table helper functions.
fmod_str(9)file module switch table helper functions.
fmodsw(9)the SVR 4 STREAMS module switch table.
fmodsw_list(9)the SVR 4 STREAMS module switch table.
fmodsw_lock(9)the SVR 4 STREAMS module switch table.
freeb(9)frees a STREAMS message block.
freelk(9)allocate or free a STREAMS link block.
freemsg(9)frees a STREAMS message.
freeq(9)deallocate a STREAMS queue pair.
freestr(9)deallocate a STREAMS Stream head.
freezestr(9)freeze the state of a Stream.
frtn_t(9)allocate a STREAMS message and data block with caller supplied data buffer.
getadmin(9)get the administrative function pointer for a STREAMS module.
getmajor(9)get the internal major device number for a device.
getmid(9)get the STREAMS module id for a name.
getminor(9)get the extended minor device number for a device.
getq(9)get a message from a STREAMS message queue.
insq(9)insert a message into a STREAMS message queue.
iocblk(9)STREAMS input-output control block structure.
isdatablk(9)test a STREAMS data block for data type.
isdatamsg(9)test a STREAMS data block for data type.
kmem_alloc(9)allocate kernel memory.
kmem_alloc_node(9)allocate kernel memory.
kmem_free(9)deallocate kernel memory.
kmem_zalloc(9)allocate and zero kernel memory.
kmem_zalloc_node(9)allocate and zero kernel memory.
linkb(9)link a message block to a STREAMS message.
linkblk(9)STREAMS link block structure.
linkmsg(9)link a message block to a STREAMS message.
major_t(9)get the internal major device number for a device.
makedevice(9)create a device from major and minor device numbers.
max(9)determine the maximum of two integers.
mblk_t(9)STREAMS message block structure.
min(9)determine the minimum of two integers.
minor_t(9)get the extended minor device number for a device.
modID_t(9)get the STREAMS module id for a name.
module_info(9)STREAMS module information structure.
module_stat(9)STREAMS module statistics structure.
module_stat_t(9)STREAMS module statistics structure.
msgb(9)STREAMS message block structure.
msgdsize(9)calculate the size of the data in a STREAMS message.
msgpullup(9)pull up bytes in a STREAMS message.
msgsize(9)calculate the size of the message blocks in a STREAMS message.
noenable(9)disable a STREAMS message queue from being scheduled.
pcmsg(9)test a data block message type for priority control.
pullupmsg(9)pull up the bytes in a STREAMS message.
put(9)invoke the put procedure for a STREAMS driver of module with a STREAMS message.
putbq(9)put a message back on a STREAMS message queue.
putctl(9)put a control message on a STREAMS message queue.
putctl1(9)put a one-byte control message on a STREAMS message queue.
putctl2(9)put a two-byte control message on a STREAMS message queue.
putnext(9)put a message on the downstream STREAMS message queue.
putnextctl(9)put a control message on the next STREAMS message queue.
putnextctl1(9)put a one-byte control message on the next STREAMS message queue.
putnextctl2(9)put a two-byte control message on the next STREAMS message queue.
putq(9)put a message on a STREAMS message queue.
qattach(9)attach a module onto a STREAMS file.
qbackenable(9)perform back enabling on a STREAMS queue.
qband(9)queue band structure.
qband_t(9)queue band structure.
qclose(9)close a STREAMS driver or module.
qcountstrm(9)add all counts on all STREAMS message queues in a Stream.
qdelete(9)delete a queue pair from a Stream.
qdetach(9)detach a module from a STREAMS file.
qenable(9)schedule a STREAMS message queue service procedure.
qfields(9)set attributes of a STREAMS message queue.
qfields_t(9)set attributes of a STREAMS message queue.
qi_putp(9)STREAMS driver or module put procedure.
qi_putp_t(9)STREAMS driver or module put procedure.
qi_qadmin(9)STREAMS driver or module admin routine.
qi_qadmin_t(9)STREAMS driver or module admin routine.
qi_qclose(9)STREAMS driver or module close routine.
qi_qclose_t(9)STREAMS driver or module close routine.
qi_qopen(9)STREAMS driver or module open routine.
qi_qopen_t(9)STREAMS driver or module open routine.
qi_srvp(9)STREAMS driver or module service procedure.
qi_srvp_t(9)STREAMS driver or module service procedure.
qinit(9)STREAMS queue initialization structure.
qinsert(9)insert a queue pair beneath another queue pair in a Stream.
qopen(9)call a STREAMS driver or module open routine.
qprocsoff(9)disable STREAMS message queue processing for multi-processing.
qprocson(9)enable a STREAMS message queue for multi-processing.
qready(9)test if queue procedures are scheduled.
qreply(9)replies to a message from a STREAMS message queue.
qscan(9)place a queue on the scan list.
qsize(9)return the number of messages on a queue.
queue(9)STREAMS message queue structure.
queue_t(9)STREAMS message queue structure.
register_clone(9)register a clone(4) minor.
register_cmajor(9)register external device major number.
register_ioctl32(9)register a 32-bit IO control command.
register_strdev(9)register a STREAMS device.
register_strdrv(9)register a STREAMS driver.
register_strlog(9)register a STREAMS logger.
register_strmod(9)register a STREAMS module.
register_strnod(9)register a STREAMS minor device node.
rmvb(9)remove a message block from a STREAMS message.
rmvq(9)remove a message from a STREAMS message queue.
runqueues(9)run queue service procedures and other asynchronous STREAMS events.
sd_get(9)acquire and release a reference to the Stream head.
sd_put(9)acquire and release a reference to the Stream head.
sdev_add(9)character device switch table helper functions.
sdev_del(9)character device switch table helper functions.
sdev_get(9)character device switch table helper functions.
sdev_ini(9)character device switch table helper functions.
sdev_put(9)character device switch table helper functions.
sdev_rel(9)character device switch table helper functions.
sealloc(9)STREAMS event allocators.
sefree(9)STREAMS event allocators.
setq(9)set sizes and procedures associated with a STREAMS message queue.
setqsched(9)invoke the STREAMS scheduler.
setsq(9)set synchronization queues, sizes and procedures associated with a STREAMS message queue.
skballoc(9)allocate a STREAMS message and data block with a caller supplied socket buffer.
spec_open(9)STREAMS special device shadow file system.
spec_reparent(9)STREAMS special device shadow file system.
specfs_mount(9)STREAMS special device shadow file system.
specfs_umount(9)STREAMS special device shadow file system.
str_close(9)Stream head module procedures.
str_open(9)Stream head module procedures.
streamtab(9)STREAMS module definition structure.
streamtab_t(9)STREAMS module definition structure.
strgetpmsg(9)perform a getpmsg(2s) operation on a Stream head.
strioctl(9)perform a ioctl(2s) operation on a Stream head.
strlog(9)pass a message to the STREAMS logger.
strm_f_ops(9)file operations for Stream heads.
stroptions(9)STREAMS Stream head options structure.
strpoll(9)perform a poll(2s) operation on a Stream head.
strputpmsg(9)perform a putpmsg(2s) operation on a Stream head.
strqget(9)get attributes of a STREAMS message queue.
strqset(9)set attributes of a STREAMS message queue.
strread(9)perform a read(2s) operation on a Stream head.
strrput(9)Stream head module procedures.
strsendpage(9)perform a sendfile(2s) operation on a Stream head.
strthread(9)the SVR 4 STREAMS scheduler thread structure and array.
strthreads(9)the SVR 4 STREAMS scheduler thread structure and array.
strwput(9)Stream head module procedures.
strwrite(9)perform a write(2s) operation on a Stream head.
strwsrv(9)Stream head module procedures.
sysctl_str_nstrpush(9)introduction to STREAMS kernel functions.
sysctl_str_strctlsz(9)introduction to STREAMS kernel functions.
sysctl_str_strmsgsz(9)introduction to STREAMS kernel functions.
testb(9)test if a STREAMS message can be allocated.
timeout(9)start a timer.
timeout_id_t(9)start a timer.
timo_fcn_t(9)start a timer.
toid_t(9)start a timer.
unbufcall(9)remove a STREAMS buffer callback.
unfreezestr(9)thaw the state of a Stream queue.
unlinkb(9)unlink a message block from a STREAMS message.
unlinkmsg(9)unlink a message block from a STREAMS message.
unregister_clone(9)unregister a clone(4) minor.
unregister_cmajor(9)unregister external device major number.
unregister_ioctl32(9)unregister a 32-bit IO control command.
unregister_strdev(9)unregister a STREAMS device.
unregister_strdrv(9)unregister a STREAMS driver.
unregister_strmod(9)unregister a STREAMS module.
unregister_strnod(9)unregister a STREAMS minor device node.
untimeout(9)stop a timer.
unweldq(9)unweld two queues.
vcmn_err(9)print a kernel command error.
vstrlog(9)pass a message to the STREAMS logger.
vstrlog_t(9)register a new STREAMS log device.
weld_arg_t(9)weld two (or four) queues together.
weld_fcn_t(9)weld two (or four) queues together.
weldq(9)weld two (or four) queues together.
xmsgsize(9)calculate the size of message blocks in a STREAMS message.

5 Porting

Linux Fast-STREAMS provides a rich set of STREAMS functions, DDI/DKI functions and utilities based on SVR 4.2 MP for the development of STREAMS modules and drivers. Although these functions and capabilities provide all of the utilities necessary for the development of STREAMS modules and drivers, it represents the common set of functions provided by other STREAMS implementations.

Some other STREAMS implementations provide interfaces, utilities and helper functions specific to those implementations. Where STREAMS implementations differ the most is in the manner in which they configure and register STREAMS drivers and modules for interface to the operating system, including registration functions, device numbering, creation of minor device nodes, administration and other mechanisms not specified by the System V Release 4 Programmer's Guide – STREAMS.

To assist with porting of STREAMS drivers and modules from other STREAMS implementations and UNIX based operating systems to Linux Fast-STREAMS, Linux Fast-STREAMS provides a separate STREAMS Compatibility add-on package, called strcompat-0.9.2.7,12 that provide source level compatibility with a wide range of mainstream STREAMS implementations and significant groups of compatibility and helper functions (such as those from Solaris and Mentat). These compatibility packages also provide separate demand loadable kernel modules that provide the additional compatibility functionality with Linux Fast-STREAMS.

Perhaps one of the most important ports to Linux Fast-STREAMS is from the deprecated and deficient LiS package to Linux Fast-STREAMS. The STREAMS Compatibility package, strcompat, also provides a source level compatibility module that provides source level compatibility to LiS to ease porting LiS drivers and modules to the superior Linux Fast-STREAMS.

In general, when porting to Linux Fast-STREAMS from another STREAMS implementation, the following items will need the most attention:

Header Files
The STREAMS and operating system specific header files that must be included by kernel modules to implement STREAMS drivers or modules are specific to each STREAMS implementation. Although there are some basic header files to include (sys/stream.h, sys/strconf.h, sys/ddi.h, sys/cmn_err.h, sys/dki.h, sys/kmem.h), the order in which these headers are included and the additional operating system specific headers are implementation specific. See the example drivers and modules for the header files that are necessary for Linux Fast-STREAMS STREAMS modules and drivers.
Kernel Module Mechanism
The mechanism for creating, configuring and loading kernel modules is specific to the operating system implementation. Linux Fast-STREAMS uses the normal Linux mechanisms for kernel modules also for STREAMS drivers and modules.
Configuration and Registration
The STREAMS driver or module will need to be converted to use the Linux Fast-STREAMS configuration and registration mechanisms. See register_strdev(9), unregister_strdev(9), register_strmod(9) and unregister_strmod(9) for more specific information on the Linux Fast-STREAMS configuration and registration mechanisms.
Non-STREAMS DDI/DKI Facilities
Any of the non-STREAMS DDI/DKI facilities or operating system specific facilities that are used by the STREAMS driver or module may need to be replaced with the Linux equivalent. Examples of such facilities include basic locks, read-write locks, semaphores and mutexes, atomic integers, interrupt suppression, bus access and memory mapping functions.
Binary Modules
When STREAMS drivers or modules are released as binary objects and source code is not available, it is still possible to convert the binary module for use with Linux Fast-STREAMS. The facility to convert binary modules for use with Linux Fast-STREAMS is not, however, part of the base package and is not part of the STREAMS Compatibility package. A separate add-on package, the Binary Compatibility Modules package, strbcm-0.9.2.5 was developed explicitly for this purpose.13

5.1 Porting from LiS

Applications programs to not need to be ported, or even recompiled when they use shared libraries. Linux Fast-STREAMS provides LiS compatible shared object libraries. Applications compiled against static libraries will need to be recompiled unless Linux Fast-STREAMS was configured for STREAMS binary compatibility mode.14

In general, if no LiS specific functions are used (other than STREAMS driver or module registration functions), porting of LiS drivers and modules to Linux Fast-STREAMS is straightforward. Linux Fast-STREAMS provides several STREAMS drivers and modules that are common to both OpenSS7 Linux Fast-STREAMS and LiS releases. These drivers and modules provide examples of how to write STREAMS drivers or modules that can run under either LiS or Linux Fast-STREAMS. The common modules and drivers are as follows:

src/drivers/echo.c echo(4)
src/drivers/mux.c mux(4)
src/drivers/nuls.c nuls(4)
src/modules/nullmod.c nullmod(4)
src/modules/sc.c sc(4)
src/modules/testmod.c testmod(4)

When built for Linux Fast-STREAMS, ‘C’ preprocessor symbol ‘LFS’ is defined; when built for LiS, ‘LIS’ is defined.

LiS provides many simple wrapper functions that are Linux kernel functions with ‘lis_’ prepended to the name. Aside from licensing issues associated with using these wrapper functions, in many cases it is possible to simply drop the ‘lis_’ from the function call and use the Linux functions directly. This is true for most spin locks, read-write locks, semaphores, mutexes, atomic integers, bus access and memory mapping functions.

When many or specific LiS functions calls are necessary, it is better to use the LiS compatibility module present in the strcompat-0.9.2.7 package.

5.2 Porting from SVR 4.2 MP

When porting from SVR 4.2 MP or a STREAMS implementation based closely on SVR 4.2 MP, such as SUPER-UX, UXP/V, IRIX or many of the real-time operating system implementations (e.g. VxWorks), it is possible to port directly to Linux Fast-STREAMS without using the STREAMS Compatibility package. Event when porting from AIX, HP-UX and OSF/1 it is possible to avoid using the compatibility package.

Most pseudo-device drivers and modules should not require any special facilities beyond basic locks and porting may be straightforward. Where extensive implementation specific DDI/DKI or operating system functions are required, it is better to use the STREAMS Compatibility package and modules closest to the specific implementation being ported from.

5.3 Porting from Solaris

When porting from Solaris there are both STREAMS facilities and extensive DDI/DKI facilities that differ greatly from basic SVR 4.2 MP STREAMS and DDI/DKI functions. For porting all but the most trivial of STREAMS drivers and modules written specifically for Solaris, it is better to use the STREAMS Compatibility package and the Solaris compatibility module provided by that package.15

5.4 Porting from UnixWare

When porting from UnixWare there are extensive operating system facilities that differ greatly from basic Linux facilities. For the most part these are basic locks, read-write locks, condition variables, sleep locks, atomic integers, bus access and mapping functions. Although Linux provides equivalents in most of these categories, the STREAMS Compatibility package contains a compatibility module for UnixWare that provides source compatibility with most of these functions. It is recommended that all but the most trivial of UnixWare drivers and modules use the STREAMS Compatibility package when porting.

5.5 Porting from Mentat

When porting a STREAMS driver or module from a Mentat implementation (such as AIX, HP-UX, OSF/1, Mac OT) that makes heavy use of the Mentatmi_’ or ‘mps_’ helper functions, it is best to use the OpenSS7 implementations of those functions available in the STREAMS Compatibility package directly. The STREAMS Compatibility package provides a Mentat Portable STREAMS compatibility module that provides implementations of the Mentat functions found in AIX, OSF/1 and Mac OT.16

6 Conformance

6.1 Standards Compliance

Linux Fast-STREAMS was designed and implemented to be compliant with as many standards impinging on STREAMS as possible. There are three areas of standards compliance as follows:

6.1.1 User Interface Compliance

The STREAMS user interface standards are primarily specified by the IEEE and OpenGroup standards and take the form of the POSIX 2003 and Single UNIX Specification standards simultaneously released by the OpenGroup in conjunction with IEEE. The latest POSIX/IEEE/OpenGroup standard provide an XSI extension that includes the STREAMS user interface. For the most part, the OpenGroup XSI interface is completely compatible with the user interface described in the System V Release 4 Programmer's Manual – STREAMS, and where it does not, Stream head options are provided to select between the default OpenGroup XSI behaviour and the traditional SVR 4 behaviour.

Most of the XSI specifications of the OpenGroup describe the behaviour of the Stream head and the behaviour of specific STREAMS drivers or modules (such as pipes, FIFOs and terminals). Also described is the poll(2s) behaviour, generation of signals, and read(2s) and write(2s) behaviour as it applies to STREAMS character special devices.17

User interface compliance of the Linux Fast-STREAMS is tested with custom validation test suites that ship with the package. See Conformance Test Programs for more information on conformance and validation test suites.

6.1.2 Service Interface Compliance

The OpenGroup (now and in previous incarnations) have issued standardized service interface specifications as part of the Common Application Environment (CAE) specifications. These service interface specifications usually concern networking interfaces such as the Data Link Provider Interface (DLPI), the Network Provider Interface (NPI), the Transport Provider Interface (TPI), the X/Open Transport Interface (XTI) and the Sockets API. Although these standards impinge upon various networking add-on packages for Linux Fast-STREAMS, they do not impinge upon the base STREAMS package documented here. See the Installation and Reference Manual for the appropriate add-on package.

6.1.3 Kernel Interface Compliance

The STREAMS kernel interfaces, DDI/DKI and other facilities available to the STREAMS driver or module writer has not been subjected to formal standardization. For the most part, the descriptions that are present in the System V Programmer's Manual – STREAMS provide the most definitive ipso facto standard for STREAMS implementation. In addition to this, some STREAMS implementations have provided some enhancements or restrictions over the SVR 4 descriptions. Perhaps the most extensive embellishments have been provided for the Solaris implementation of STREAMS.

Linux Fast-STREAMS has been implemented to provide maximum compatibility over a wide range of STREAMS implementations based on SVR 4 and provides additional capabilities similar to those specific embellishments found in implementations such as Solaris through an add-on STREAMS Compatibility package.

The most delicate areas of compatibility across STREAMS implementations regard, not the use of STREAMS or DDI/DKI functions from within the STREAMS environment, but the invocation of STREAMS functions from outside the STREAMS environment. In particular, use of private locks and synchronization in the face of interrupts and external asynchronous callbacks is where implementations deviate the greatest. Linux Fast-STREAMS attempts to address these differences by providing a greater level of assurance and wider range of calling contexts for each of the STREAMS facilities.

Kernel interface compliance of the Linux Fast-STREAMS to SVR 4 specifications is tested with custom validation test suites, test modules and test drivers that ship with the package. See Conformance Test Programs for more information on conformance and validation test suites.

6.2 STREAMS Compatibility

Linux Fast-STREAMS provides a high degree of compatibility with other STREAMS implementation as listed below. Through the separate add-on STREAMS Compatibility package, source level compatibility is also provided.

— SVR 3.2
Linux Fast-STREAMS provides a degree of operational compatibility with SVR 3.2 to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with SVR 3.2.
— SVR 4.2 ES/MP
Linux Fast-STREAMS provides a high degree of operational compatibility with SVR 4.2 ES/MP to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with SVR 4.2 ES/MP.
— Mentat Portable STREAMS
Linux Fast-STREAMS provides a high degree of operational compatibility with Mentat Portable STREAMS to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with Mentat Portable STREAMS.
— AIX 5L Version 5.1
Linux Fast-STREAMS provides a high degree of operational compatibility with AIX 5L Version 5.1 to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with AIX 5L Version 5.1.
— HP-UX 11.0i v2
Linux Fast-STREAMS provides a high degree of operational compatibility with HP-UX 11.0i v2 to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with HP-UX 11.0i v2.
— OSF/1 1.2/Digital UNIX/True 64
Linux Fast-STREAMS provides a high degree of operational compatibility with OSF/1 1.2/Digital UNIX to ease portability and common comprehension.
— UnixWare 7.1.3 (OpenUnix 8)
Linux Fast-STREAMS provides a high degree of operational compatibility with UnixWare 7.1.3 (OpenUnix 8) to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with UnixWare 7.1.3 (OpenUnix 8).
— Solaris 9/SunOS 5.9
Linux Fast-STREAMS provides a high degree of operational compatibility with Solaris 9/SunOS 5.9 to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with Solaris 9/SunOS 5.9.
— IRIX 6.5.17
Linux Fast-STREAMS provides a high degree of operational compatibility with IRIX 6.5.17 to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with IRIX 6.5.17.
— Mac OS 9 Open Transport
Linux Fast-STREAMS provides a high degree of operational compatibility with Mac OS 9 Open Transport to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with Mac OS 9 Open Transport.
— SUPER-UX
Linux Fast-STREAMS provides a high degree of operational compatibility with SUPER-UX to ease portability and common comprehension.
— UXP/V
Linux Fast-STREAMS provides a high degree of operational compatibility with UXP/V to ease portability and common comprehension.
— LiS-2.16.18 and LiS 2.18.0
Linux Fast-STREAMS provides a high degree of operational compatibility with LiS 2.16.18 and LiS 2.18.0 to ease portability and common comprehension. to ease portability and common comprehension. Specific kernel utilities are provided by the STREAMS Compatibility package to provide full source level compatibility with LiS 2.16.18 and LiS 2.18.0.

For additional details, see About This Manual.

7 Releases

This is the OpenSS7 Release of the Linux Fast-STREAMS core, tools, drivers and modules that implement the Linux Fast-STREAMS SVR 4.2 MP STREAMS utility for Linux. This package is intended as a replacement package for Linux STREAMS (LiS).

The following sections provide information on Linux Fast-STREAMS releases as well as compatibility information of OpenSS7 release to mainstream UNIX releases of the core, modules and drivers, as well as Linux kernel compatibility.

7.1 Prerequisites

The quickest and easiest way to ensure that all prerequisites are met is to download and install this package from within the OpenSS7 Master Package, openss7-0.9.2.G, instead of separately.

Prerequisites for the Linux Fast-STREAMS package are as follows:

  1. Linux distribution, somewhat Linux Standards Base compliant, with a 2.4 or 2.6 kernel and the appropriate tool chain for compiling out-of-tree kernel modules. Most recent Linux distributions are usable out of the box, but some development packages must be installed. For more information, see Compatibility.

    − A fairly LSB compliant GNU/Linux distribution.18
    − Linux 2.4 kernel (2.4.10 - 2.4.27), or
    − Linux 2.6 kernel (2.6.3 - 2.6.26);
    − glibc2 or better.
    − GNU groff (for man pages).19
    − GNU texinfo (for info files).
    − GNU bison and flex (for config programs).
    − net-snmp (for SNMP agents).20

If you need to rebuild the package from sources with modifications, you will need a larger GNU tool chain as described in See Downloading from CVS.

7.2 Compatibility

This section discusses compatibility with major prerequisites.

7.2.1 GNU/Linux Distributions

Linux Fast-STREAMS is compatible with the following Linux distributions:21

  • CentOS Enterprise Linux 3.4 (centos34) TBD
  • CentOS Enterprise Linux 4.0 (centos4) TBD
  • CentOS Enterprise Linux 4.92 (centos49) TBD
  • CentOS Enterprise Linux 5.0 (centos5)
  • CentOS Enterprise Linux 5.1 (centos51)
  • CentOS Enterprise Linux 5.2 (centos52)
  • Debian 3.0r2 Woody (deb3.0) TBD
  • Debian 3.1r0a Sarge (deb3.1) TBD
  • Debian 4.0r1 Etch (deb4.0)
  • Debian 4.0r2 Etch (deb4.0)
  • Debian 4.0r3 Etch (deb4.0)
  • Fedora Core 1 (FC1) TBD
  • Fedora Core 2 (FC2) TBD
  • Fedora Core 3 (FC3) TBD
  • Fedora Core 4 (FC4) TBD
  • Fedora Core 5 (FC5) TBD
  • Fedora Core 6 (FC6) TBD
  • Fedora 7 (FC7)
  • Fedora 8 (FC8)
  • Fedora 9 (FC9)
  • Gentoo 2006.1 (untested) TBD
  • Gentoo 2007.1 (untested) TBD
  • Lineox 4.026 (LEL4) TBD
  • Lineox 4.053 (LEL4) TBD
  • Mandrakelinux 9.2 (MDK92) TBD
  • Mandrakelinux 10.0 (MDK100) TBD
  • Mandrakelinux 10.1 (MDK101) TBD
  • Mandriva Linux LE2005 (MDK102) TBD
  • Mandriva Linux LE2006 (MDK103) TBD
  • Mandriva One (untested)
  • RedHat Linux 7.2 (RH7)
  • RedHat Linux 7.3 (RH7)
  • RedHat Linux 8.0 (RH8) TBD
  • RedHat Linux 9 (RH9) TBD
  • RedHat Enterprise Linux 3.0 (EL3) TBD
  • RedHat Enterprise Linux 4 (EL4)
  • RedHat Enterprise Linux 5 (EL5)
  • SuSE 8.0 Professional (SuSE8.0) TBD
  • SuSE 9.1 Personal (SuSE9.1) TBD
  • SuSE 9.2 Professional (SuSE9.2) TBD
  • SuSE OpenSuSE (SuSEOSS) TBD
  • SuSE 10.0 (SuSE10.0) TBD
  • SuSE 10.1 (SuSE10.1) TBD
  • SuSE 10.2 (SuSE10.2) TBD
  • SuSE 10.3 (SuSE10.3) TBD
  • SuSE 11.0 (SuSE11.0)
  • SLES 9 (SLES9) TBD
  • SLES 9 SP2 (SLES9) TBD
  • SLES 9 SP3 (SLES9) TBD
  • SLES 10 (SLES10)
  • Ubuntu 5.10 (ubu5.10) TBD
  • Ubuntu 6.03 LTS (ubu6.03) TBD
  • Ubuntu 6.10 (ubu6.10) TBD
  • Ubuntu 7.04 (ubu7.04) TBD
  • Ubuntu 7.10 (ubu7.10)
  • Ubuntu 8.04 (ubu8.04)
  • WhiteBox Enterprise Linux 3.0 (WBEL3) TBD
  • WhiteBox Enterprise Linux 4 (WBEL4) TBD

When installing from the tarball (see Installing the Tar Ball), this distribution is probably compatible with a much broader array of distributions than those listed above. These are the distributions against which the current maintainer creates and tests builds.

7.2.2 Kernel

The Linux Fast-STREAMS package compiles as a Linux kernel module. It is not necessary to patch the Linux kernel to build or use the package.22 Nor do you have to recompile your kernel to build or use the package. OpenSS7 packages use autoconf scripts to adapt the package source to your existing kernel. The package builds and runs nicely against production kernels from the distributions listed above. Rather than relying on kernel versions, the autoconf scripts interrogate the kernel for specific features and variants to better adapt to distribution production kernels that have had patches applied over the official kernel.org sources.

The Linux Fast-STREAMS package is compatible with 2.4 kernel series after 2.4.10 and has been tested up to and including 2.4.27. It has been tested from 2.6.3 up to and including 2.6.26 (with Fedora 9, openSUSE 11.0 and Ubuntu 8.04 patchsets). Please note that your mileage may vary if you use a kernel more recent than 2.6.26.4: it is difficult to anticipate changes that kernel developers will make in the future. Many kernels in the 2.6 series now vary widely by release version and if you encounter problems, try a kernel within the supported series.

UP validation testing for kernels is performed on all supported architectures. SMP validation testing was initially performed on UP machines, as well as on an Intel 3.0GHz Pentium IV 630 with HyperThreading enabled (2x). Because HyperThreading is not as independent as multiple CPUs, SMP validation testing was limited. Current releases have been tested on dual 1.8GHz Xeon HP servers (2x) as well as dual quad-core SunFire (8x) servers.

It should be noted that, while the packages will configure, build and install against XEN kernels, that problems running validation test suites against XEN kernels has been reported. XEN kernels are explicitly not supported. This may change at some point in the future if someone really requires running OpenSS7 under a XEN kernel.

7.2.3 Architectures

The Linux Fast-STREAMS package compiles and installs on a wide range of architectures. Although it is believed that the package will work on all architectures supported by the Linux kernel being used, validation testing has only been performed with the following architectures:

  • ix86
  • x86_64
  • ppc (MPC 860)
  • ppc64

32-bit compatibility validation testing is performed on all 64-bit architectures supporting 32-bit compatibility. If you would like to validate an OpenSS7 package on a specific machine architecture, you are welcome to sponsor the project with a test machine.

7.2.4 Linux STREAMS

Linux Fast-STREAMS provides a suitable replacement for the (now deprecated) Linux STREAMS (LiS) 2.18.0 package formerly maintained by Dave Goethe of GCOM.

7.3 Release Notes

The sections that follow provide information on OpenSS7 releases of the Linux Fast-STREAMS package.

Major changes for release streams-0.9.2.4

This is the thirteenth OpenSS7 Project release of Linux Fast-STREAMS. LiS was fully deprecated as of the previous release and Linux Fast-STREAMS is the only STREAMS package contained in the OpenSS7 Master Package (since openss7-0.9.2.D).

This release is a stable, production grade release and is part of the OpenSS7 Master Package (openss7-0.9.2.G). The release includes maintenance support for recent distributions and tool chain, but also includes some performance and feature upgrades and inspection bug fixes. It deprecates previous releases. Please upgrade before reporting bugs on previous releases.

This release is primarily a maintenance release.

Major features since the last public release are as follows:

  • Minor documentation corrections.
  • Kernel module license made explicit "GPL v2". And then changed back to "GPL".
  • License upgrade to AGPL Version 3.
  • Modifications to build under Fedora2.6.22.5-49’ kernel. These changes also support ‘2.6.22.9-91.fc7’ kernel.
  • Added SNMP MIBs and AgentX sub-agent for STREAMS. This is a rather significant addition to Linux Fast-STREAMS which permits remote management of the entire STREAMS subsystem using SNMP. The agent is compatable with net-snmp and ucd-snmp back to ucd-snmp 4.2.5. This includes updates to the build process to support net-snmp packages all the way back to RedHat 7.2.
  • Added the ability for the sc(4) STREAMS Configuration module to allow tuning STREAMS module info parameters and collect general purpose STREAMS statistics. Also, the module generates signals (‘SIGPOLL’) when STREAMS configuration changes. See sc(4) for more information.

    Also added a STREAMS configuration change notification registration function for use by sc(4). See streams_notify(9), streams_register_notifier(9) and streams_unregister_notifier(9) for more information.

  • Ability to strap out major documentation build and installation primarily for embedded targets.
  • Improvements to common build process for embedded and cross-compile targets.
  • Support for flex 2.5.33 in maintainer mode.
  • Higher performance and updated performance paper.
  • Fixed two POSIX compilance quirks and one soft-lockup when using M_READ. See BUGS in the release for more information.
  • Added workaround for use of crash(8).
  • Modifications to build under Fedora2.6.25-45.fc9’ and ‘2.6.26.5-45.fc9’ kernels.
  • Updated tool chain to m4-1.4.12, autoconf-2.63 and texinfo-4.13.
  • Conversion of RPM spec files to common approach for major subpackages.
  • Updated references database for manual pages and roff documents.
  • Added test case 3.1.11.4 and modified test cases 3.2.1, 3.5.1 and 3.6.1 for the test-streams tests suite executable to test bug fixes and avoid regressions. See bug #016 and #017 in BUGS.
  • Build system now builds yum(8) repositories for RPMs and apt-get(8) repositories for DEBs. Installation documentation has been updated to include details of repository install sourcesref.
  • Added MODULE_VERSION to all modules and drivers.

This is a public stable production grade release of the package: it deprecates previous releases. Please upgrade to the current release before reporting bugs.

As with other OpenSS7 releases, this release configures, compiles, installs and builds RPMs and DEBs for a wide range of Linux 2.4 and 2.6 RPM- and DPKG-based distributions, and can be used on production kernels without patching or recompiling the kernel.

This package is publicly released under the GNU Affero General Public License Version 3. The release is available as an autoconf tarball, SRPM, DSC, and set of binary RPMs and DEBs. See the downloads page for the autoconf tarballs, SRPMs and DSCs. For tarballs, SRPMs, DSCs and binary RPMs and DEBs, see the streams package page.

See http://www.openss7.org/codefiles/streams-0.9.2.4/ChangeLog and http://www.openss7.org/codefiles/streams-0.9.2.4/NEWS in the release for more information. Also, see the STREAMS.pdf manual in the release (also in html http://www.openss7.org/STREAMS_manual.html).

For the news release, see http://www.openss7.org/rel20081029_K.html.

Major changes for release streams-0.9.2.3

This is the twelveth OpenSS7 Project release of Linux Fast-STREAMS. LiS was fully deprecated as of the previous release and Linux Fast-STREAMS is the only STREAMS package contained in the OpenSS7 Master Package (since openss7-0.9.2.D).

This release is a stable, production grade release. The release includes maintenance support for recent distributions and tool chain, but also includes some performance and feature upgrades and inspection bug fixes.

Major features since the last public release are as follows:

  • Support build on openSUSE 10.2.
  • Support build on Fedora 7 and 2.6.21 kernel.
  • The strace(8), strerr(8) utilities and log(4) driver have had some corrections. The STREAMS trace logger is now an excellent way for trace logging of fielded production drivers. A number of OpenSS7 drivers have already been converted to use this facility.
  • Support build on CentOS 5.0 (RHEL5).
  • Support build on Ubuntu 7.04.
  • Significant rework of the Stream head and both enabling and backenabling utilities. Handling of enabling flags QWANTR and QWANTW were not being performed quite properly. Also, service procedures for the read side stream head queue was added to defer wakeups when possible. The result is very significant performance improvements (like it wasn't fast enough already).

    STREAMS-based pipes in this package now perform 2 to 5 times (yes %200 to %500) faster than the old legacy 4.1BSD/SVR4 Linux pipes currently in the kernel: perhaps we should shout the "Fast" too.

    The impact of these performance changes is that Linux Fast-STREAMS now runs faster and looser on SMP systems: if your drivers have race conditions they will likely be exacerbated by this version.

  • Corrected a few bugs. See BUGS in the release for more information.
  • Significant rework of STREAMS syncrhonization. OSF/1-Mentat style syncrhonization levels, Solaris style perimeters, and SVR 4.2 style load refusal are fully supported. Some idiosynchracies of AIX, HP-UX, MacOT and VxWorks is also supported.
  • Updated to gettext 0.16.1.
  • Changes to support build on 2.6.20-1.2307.fc5 and 2.6.20-1.2933.fc6 kernel.
  • Supports build on Fedora Core 6.
  • Support for recent distributions and tool chains.

Major changes for release streams-0.9.2.2

This is the eleventh OpenSS7 Project release of Linux Fast-STREAMS. LiS was fully deprecated as of the previous release and Linux Fast-STREAMS is now the only STREAMS package contained in the OpenSS7 Master Package (since openss7-0.9.2.D).

This release is a stable, production grade release for Linux Fast-STREAMS. The release is primarily a maintenance release to support recent distributions and tool chain.

Major features since the last public release are as follows:

  • Fix for clone open failure locking problems, demand loading of clone minors, an error in clone minor device deregistration, and an error in queue syncrhornization. See http://www.openss7.org/codefiles/streams-0.9.2.4/BUGS in the release for more information.
  • Added feature to perform automatic reference counting of modules for the esballoc(9) free routines on Linux 2.6 kernels. See new esballoc(9).
  • Added versions to all exported symbols. Made LFS unique functions GPL export.
  • Improvements to the common build environment with better support for standalone package builds on 2.4 kernels.
  • Support for autoconf 2.61, automake 1.10 and gettext 0.16.
  • Support for Ubuntu 6.10 distribution and bug fixes for i386 kernels.

Major changes for release streams-0.9.2.1

This is the tenth OpenSS7 Project release of Linux Fast-STREAMS. The release number has been moved from the 0.9a sequence to 0.9.2 to indicate that the package has moved to a production grade. LiS has been fully deprecated by this release and Linux Fast-STREAMS is now the only STREAMS package contained in the OpenSS7 Master Package (openss7-0.9.2.D).

This release is a stable, production grade release for Linux Fast-STREAMS. The release is primarily a maintenance release. Some minor defect corrections have been applied, but no significant development has occurred. The release provides the following enhancements and fixes:

  • Testing of, and a few bug corrections to, the strlog() feature. Trace and error logging working well.
  • Support for most recent 2.6.18 kernels (including Fedora Core 5 with inode diet patch set).
  • The package now builds a replacement libLiS and libpLiS library so that user applications written to work with LiS-2.18.1 through LiS-2.18.7 do no need to be recompiled. Added versions to all library symbols in all three libraries.
  • Minor bug fixes to STREAMS library. isastream(3) and fattach(3) must not contain an asynchronous thread cancellation point, but they could. Added asynchronous thread cancellation protection to these functions to remove any thread cancellation points.
  • Now builds 32-bit compatibility libraries, as well, and tests them against 64-bit kernel modules and drivers. The ‘make installcheck’ target will now automatically test both 64-bit native and 32-bit compatibility versions, one after the other, on 64-bit platforms.
  • Many documentation updates for all OpenSS7 packages. Automated release file generation making for vastly improved and timely text documentation present in the release directory.
  • Dropped support for LiS.
  • Updated init scripts for proper addition and removal of modules.
  • Start assigning majors at major device number 231 instead of major device number 230. Assign major device number 230 explicitly to the clone device. Package will now support extended ranges of minor devices on 2.6 kernels under Linux Fast-STREAMS only. streams now supports expanded addressable minor device numbers, permitting 2^16 addressable minor devices per major device number on 2.6 kernels: LiS cannot support this change.
  • Better detection of SUSE distributions, release numbers and SLES distributions: support for additional SuSE distributions on ix86 as well as x86_64. Added distribution support includes SLES 9, SLES 9 SP2, SLES 9 SP3, SLES 10, SuSE 10.1.
  • Improved compiler flag generation and optimizations for recent gcc compilers and some idiosyncratic behaviour for some distributions (primarily SUSE).
  • Optimized compilation is now available also for user level programs in addition to kernel programs. Added new --with-optimize option to configure to accomplish this.
  • Added --disable-devel configure option to suppress building and installing development environment. This feature is for embedded or pure runtime targets that do not need the development environment (static libraries, manual pages, documentation).
  • Added send-pr script for automatic problem report generation.
  • The package will now build doxygen(1) html documentation with the 'doxy' make target. See 'make help' or README-make in the distribution for more information.

Major changes for release streams-0.7a.6.rc3

Third release candidate.

  • Minor bug fixes to STREAMS library. isastream(3) and fattach(3) must not contain an asynchronous thread cancellation point, but they could. Added asynchronous thread cancellation protection to these functions to remove any thread cancellation points.
  • The package will now build doxygen(1) html documentation with the 'doxy' make target. See 'make help' or README-make in the distribution for more information.
  • Now builds 32-bit compatibility libraries and tests them against 64-bit kernel modules and drivers. The ‘make installcheck’ target will now automatically test both 64-bit native and 32-bit compatibility versions, one after the other, on 64-bit platforms.
  • Added versions to all library symbols.
  • Automated release file generation making for vastly improved and timely text documentation present in the release directory.
  • Many documentation updates for all OpenSS7 packages.
  • This release candidate includes the changes made to the strsctp drivers at the 2006 SCTP Interop at the University of British Columbia. This version was interoperability tested with all implementations present.
  • This release candidate provides support for additional SuSE distributions on ix86 as well as x86_64. Added distribution support includes SLES 9, SLES 9 SP2, SLES 9 SP3, SLES 10, SuSE 10.1.
  • Better detection of SUSE distributions, release numbers and SLES distributions.
  • Optimized compilation is now available also for user level programs in addition to kernel programs. Added new --with-optimize option to configure to accomplish this.
  • Improved compiler flag generation and optimizations for recent gcc compilers and some idiosyncratic behaviour for some distributions (primarily SUSE):

    Remove -fno-reorder-blocks and -fno-reorder-functions options added by some recent 2.6 Makefiles for ‘x86_64’ architecture: it impedes performance optimizations.
    Remove -ffunction-sections option added by some recent 2.6 Makefiles for ‘x86_64’ architecture: this is an insane option and should never have been used.
    Add -ffreestanding that some older 2.6 Makefiles (such as that with SLES 9 2.6.5 kernel) neglect to add to the gcc command line.
    SLES 10 expands the directory before autoconf.h on the gcc command line for some reason. configure script watches out for this now.
  • Updated init scripts for proper addition and removal of modules.
  • Start assigning majors at major device number 231 instead of major device number 230. Assign major device number 230 explicitly to the clone device.
  • streams now supports expanded addressable minor device numbers, permitting 2^16 addressable minor devices per major device number on 2.6 kernels: LiS cannot support this change.

This release is an internal release candidate and was not publicly released.

Major changes for release streams-0.7a.6.rc2

Second release candidate.

This release candidate also contains the results of performance testing of the new second generation UDP driver (implemented completely in STREAMS instead of using an internal socket).

This release candidate also contains support for SuSE 10.1.

This release is an internal release candidate and was not publicly released.

Major changes for release streams-0.7a.6rc1

Release candidate for Mark Fugate.

Added ‘--enable-develconfigure option for embedded targets. Added send-pr script for automatic problem report generation.

This release is an internal release candidate and was not publicly released.

Major changes for release streams-0.7a.5

This release is primarily to support additional compilers (gcc 4.0.2), architectures (x86_64, SMP, 32-bit compatibility), recent Linux distributions (EL4, SuSE 10, LE2006, OpenSuSE) and kernels (2.6.15).

  • Changes to wait queues. Split single wait queue into four independent wait queues. Reworked wait queues for both old style (2.4) and new style (2.6) semantics.
  • Changes to satisfy gcc 4.0.2 compiler.
  • Corrected build flags for Gentoo and 2.6.15 kernels as reported on mailing list. Build and run tested on FC4 i686 and x86_64 kernels based on 2.6.15.
  • Corrections for and testing of 64-bit clean compile and test runs on x86_64 architecture. Some bug corrections resulting from gcc 4.0.2 compiler warnings.
  • Initial corrections for and testing of SMP operation on Intel 630 Hyper-Threaded SMP on x86_64. This package should now run well on N-way Xeons even with Hyper-Threading enabled.
  • Corrections and validation of 32-bit compatibility over 64-bit on x86_64. Should apply well to other 64-bit architectures as well.

This is a public beta test release of the package.

Major changes for release streams-0.7a.4

This is primarily a bug fixes release and corrections resulting from testing.

Major changes for release streams-0.7a.3

With this release version numbers were changed to reflect an upstream version only to be consistent with other OpenSS7 package releases. All RPM release numbers will be ‘-1$(PACKAGE_RPMEXTRA)’ and all Debian release numbers will be ‘_0’. If you wish to apply patches and release the package, please bump up the release number and apply a suitable release suffix for your organization. We leave Debian release number ‘_1’ reserved for your use, so you can still bundle the source in the .dsc file.

Major changes for this release include build against Linux 2.6 kernels and popular distributions based on the 2.6 kernel as well as wider distribution support.

This was an internal beta test release and was not released publicly.

Major changes for release streams-0.7a-3

Updates to common build process. Documentation updates.

This was an internal alpha test release and was not released publicly.

Major changes for release streams-0.7a-2

Removed all XTI/TLI and Linux networking code, headers and documentation from streams distribution and set epoch at 0. Linux networking code has been migrated to the strxnet, strinet and strsctp packages. The purpose for doing this was to allow the Linux networking to build against Linux Fast-STREAMS as well as Linux STREAMS and is a preparation for phasing out LiS and phasing in LfS.

This was an internal alpha test release and was not released publicly.

Initial release streams-0.7a-1

This is the initial release of the Linux Fast-STREAMS package for Linux. This is intended as a high-performance, production replacement for Linux STREAMS (LiS). Linux Fast-STREAMS has the following features:

  • optimized for Linux kernels.
  • prepared for mainstream Linux kernel adoption.
  • lindented and follows kernel coding practises.
  • compatibility modes for AIX, HPUX, OSF, Solaris, UnixWare, SVR 4.2 and LiS.
  • supports all major SVR4.2 variants.
  • licensed under GPL with commercial licensing available.
  • supports full SVR 4.2 MP synchronization models.
  • runs at SoftIRQ.
  • provides common SVR 4.2 system tunable parameters and sysctls.
  • provides /proc file system access for debugging and performance tuning.
  • provides a full set of common STREAMS modules and drivers.
  • provides full name-streams device and shadow special file system support.

This was an internal alpha test release and was not released publicly.

7.4 Maturity

The OpenSS7 Project adheres to the following release philosophy:

  • pre-alpha release
  • alpha release
  • beta release
  • gamma release
  • production release
  • unstable release

7.4.1 Pre-Alpha Releases

Pre-alpha releases are releases that have received no testing whatsoever. Code in the release is not even known to configure or compile. The purpose of a pre-alpha release is to make code and documentation available for inspection only, and to solicit comments on the design approach or other characteristics of the software package.

Pre-alpha release packages ship containing warnings recommending that the user not even execute the contained code.

7.4.2 Alpha Releases

Alpha releases are releases that have received little to no testing, or that have been tested and contains known bugs or defects that make the package unsuitable even for testing. The purpose for an alpha release are the same as for the pre-alpha release, with the additional purpose that it is an early release of partially functional code that has problems that an external developer might be willing to fix themselves and contribute back to the project.

Alpha release packages ship containing warnings that executing the code can crash machines and might possibly do damage to systems upon which it is executed.

7.4.3 Beta Releases

Beta releases are releases that have received some testing, but the testing to date is not exhaustive. Beta release packages do not ship with known defects. All known defects are resolved before distribution; however, as exhaustive testing has not been performed, unknown defects may exist. The purpose for a beta release is to provide a baseline for other organizations to participate in the rigorous testing of the package.

Beta release packages ship containing warnings that the package has not been exhaustively tested and that the package may cause systems to crash. Suitability of software in this category for production use is not advised by the project; however, as always, is at the discretion of the user of the software.

7.4.4 Gamma Releases

Gamma releases are releases that have received exhaustive testing within the project, but external testing has been minimal. Gamma release packages do not ship with known defects. As exhaustive internal testing has been performed, unknown defects should be few. Please remember that there is NO WARRANTY on public release packages.

Gamma release packages typically resolve problems in previous beta releases, and might not have had full regression testing performed. Suitability of software in this category for production use is at the discretion of the user of the software. The OpenSS7 Project recommends that the complete validation test suites provided with the package be performed and pass on target systems before considering production use.

7.4.5 Production Releases

Production releases are releases that have received exhaustive testing within the project and validated on specific distributions and architectures. Production release packages do not ship with known defects. Please remember that there is NO WARRANTY on public release packages.

Production packages ship containing a list of validated distributions and architectures. Full regression testing of any maintenance changes is performed. Suitability of software in this category for production use on the specified target distributions and architectures is at the discretion of the user. It should not be necessary to preform validation tests on the set of supported target systems before considering production use.

7.4.6 Unstable Releases

Unstable releases are releases that have received extensive testing within the project and validated on a a wide range of distributions and architectures; however, is has tested unstable and found to be suffering from critical problems and issues that cannot be resolved. Maintenance of the package has proved impossible. Unstable release packages ship with known defects (and loud warnings). Suitability of software in this category for production use is at the discretion of the user of the software. The OpenSS7 Project recommends that the problems and issues be closely examined before this software is used even in a non-production environment. Each failing test scenario should be completely avoided by the application. OpenSS7 beta software is more stable that software in this category.

7.5 Bugs

7.5.1 Defect Notices

Linux Fast-STREAMS could possibly contain unknown defects. This is a production release. Nevertheless, some remaining unknown defects could possibly be harmful. Validation testing has been performed by the OpenSS7 Project and external entities on this software for the set of systems listed in the release notes. Nevertheless, the software might still fail to configure or compile on other systems. The OpenSS7 Project recommends that you validate this software for your target system before using this software. Use at your own risk. Remember that there is NO WARRANTY.23

This software is production software. As such, it is stable on validated systems but might still crash your kernel in unique circumstances. Installation of the software on a non-validated distribution might mangle your header files or Linux distribution in such a way as to make it unusable. Crashes could possibly lock your system and rebooting the system might not repair the problem. You can possibly lose all the data on your system. Because this software stands a chance of crashing your kernel, the resulting unstable system could possibly destroy computer hardware or peripherals making them unusable. You might void the warranty on any system on which you run this software. YOU HAVE BEEN WARNED.

7.5.2 Known Defects

With the exception of packages not originally created by the OpenSS7 Project, the OpenSS7 Project software does not ship with known bugs in any release stage except pre-alpha. Linux Fast-STREAMS had no known bugs at the time of release.

7.5.3 Defect History

This section contains historical bugs that were encountered during development and their resolutions. This list serves two purposes:

  1. It captures bugs encountered between releases during development that could possibly reoccur (and the Moon is made of blue cheese). It therefore provides a place for users to look if they encounter a problem.
  2. It provides a low overhead bug list between releases for developers to use as a TODO list.
Bugs
025. 2008-10-17T05:57:29+0000
putnext(q, mp)’ was checking whether procedures had been turned off on queue ‘q’. This was not correct as it is only the ‘q->q_next’ put procedure that would be executed. It should only check procedures on ‘q->q_next’.

*fixed* in streams-0.9.2.4

024. 2008-10-11T19:36:41+0000
A list delete corruption bug in the STREAMS driver and module lookup functions (e.g. __cdrv_lookup) was discovered by the list debugging in the FC9 kernel.

*fixed* in streams-0.9.2.4

023. 2008-10-11T19:36:23+0000
Not really a bug, but newer (2.6.25) kernels no longer permit registration of binary identifiers for sysctls (i.e. ctl_name). The proc filesystem entries (i.e. procname) are still permitted and ctl_name should be set to zero for these kernels. Added a check for the existence of symbol sysctl_check_table() to identify when binary registration is forbidden. Another related problem is that when binary registration of system controls is not possible, sysctl(2) becomes worthless. Unfortunately, the STREAMS MIB agent was written to use sysctl(2) and needs to be rewritten to use the /proc/sys filesystem instead ala sysctl(8).

*fixed* in streams-0.9.2.4

022. 2008-10-07T18:40:25+0000
When overriding 32-bit compatability on input-output controls conflicting from the CDROM block device with STREAMS input-output controls, the override was not properly passing CDROM input-output controls through due to a missing break statement in the override loop. This bug affected pre-2.6.11 kernels, likely manifesting itself in a non-function CDROM device while STREAMS was loaded. Bug reported and one-line fix provided by Sylvain Chouleur for DGAC.

*fixed* in streams-0.9.2.4

021. 2008-08-01T22:32:08+0000
When flushing queues the backenable bits were not being initialized to zero in __flushq(), resulting in back-enabling of bands (or the normal queue) was being performed depending on the uninitialized values in the backenable bit array. This only affected I_SETSIG signals for SWRNORM and SWBAND, and the only when flushing queues. Fix properly initializes the backenable array.

*fixed* in streams-0.9.2.4

020. 2008-07-31T04:59:41+0000
Not really a bug (for STREAMS), but when the streams.ko kernel module is loaded, the crash(8) debugger will not debug a running kernel because it finds the runqueues() exported function in the streams.ko module instead of the the static one from the kernel. This has been temporarily renamed by macro to srunqueues() (notice the leading ‘s’) until crash(8) learns to do the right thing and check that the symbol it looks up comes from the kernel instead of a kernel module.

*workaround* in streams-0.9.2.4

019. 2008-07-25T22:41:47+0000
When M_READ was being issued by the Stream Head downstream an srlock() imbalance in strsendmread() was causing soft-lockups on close for recent read-write lock implementations on CentOS 5.2 for ‘x86_64’.

*fixed* in streams-0.9.2.4

018. 2008-07-25T01:15:26+0000
Previous fix didn't work too good: returning [EAGAIN] when hung-up on getmsg(2), getpmsg(2), read(2), readv(2) instead of 0 and terminal end of file. This caused a regression on four or five other test cases.

*fixed* in streams-0.9.2.4

017. 2008-04-10T15:17:30+0000
When M_DATA is sent upstream followed by M_HANGUP, read(2s) is returning zero (0) and not permitting the data associated with the M_DATA to be read. This is a bug per documentation. read(2s) should operate as normal following a hangup until all data is read and then return zero (0).

The difficulty is that when waking up from a read sleep or when entering read the hangup condition was generating an internal [ESTRPIPE] error. This was altered so that [ESTRPIPE] is only returned during the hangup condition after the read queue has been tested and the caller is about to sleep on read.

Test cases 3.2.1, 3.5.1 and 3.6.1 in the test-streams test suite executable were altered to validate the fix for this case and curtail regressions.

*fixed* in streams-0.9.2.4

016. 2007-11-14T17:23:57+0000
Read is blocking when data has been read, O_NONBLOCK and O_NDELAY unset, RFILL unset, in non-SVR4 mode. This violates POSIX specifications.

Test case 3.1.11.4 in the test-streams test suite executable was generated to validate the fix for this case and to curtail regressions.

*fixed* in streams-0.9.2.4

015. 2007-11-14T17:19:01+0000
Dynamic allocation of major device numbers is not working on recent 2.6 kernels. Someone slipped some code in the kernel to have register_chrdev() allocate from major 255 down (again). Changed code to allocate modid according to our own rules and then request the same for a major device number. This also ensures that module ID and major are the same.

*fixed* in streams-0.9.2.4

014. 2007-05-17T21:48:24+0000
The dupb(9) utility had an obnoxious bug where it permitted the db_ref count to wrap to zero, causing buffer allocation and freeing problems. This was very difficult to debug. dupb(9) now fails if the reference count has reached 255. When dupb(9) fails, the user should check if the reference count has reached 255, and if it has, attempt a deep copyb(9) instead. At some point it might be useful to have STREAMS do the deep copy automatically. This was discovered in strsctp loopback tests where message blocks are rapidly duplicated for retransmission.

*fixed* in streams-0.9.2.3

013. 2007-05-17T21:48:06+0000
The log driver, strace, strerr and strclean utilities had some bugs. The strsctp driver now makes extensive use of strlog(9) trace and error logging and the log driver and utilities have been corrected. These facilities are now production grade.

*fixed* in streams-0.9.2.3

012. 2007-04-13T01:47:30+0000
It appears that Ubuntu 6.10 has a rather broken implementation of the LSB install_init that has been inherited from Debian (a python script, none the less). This implementation refuses to properly install a disabled service (one with an empty or missing Default-Start: tag), but, rather invokes updated-rc.d in such a way that the init script is started at runlevels ‘2 3 4 5’ instead. This was causing problems with the strace and strerr services which are normally installed disabled.

This uncovered the fact that the Debian-style init scripts were not working anyway. The scripts have been fixed and the strace and strerr utilities now default to enabled.

*fixed* in streams-0.9.2.3

011. 2007-04-10T10:56:42+0000
The strbcflag flag was never being cleared, causing infinite looping of the scheduler once the maximum number of buffers was reached. This also revealed a problem that bufcalls were being run unncecessarily (when strbcwait was set, instead of only when strbcflag was set).

*fixed* in streams-0.9.2.3

010. 2007-04-10T10:55:29+0000
The stream event sequence number was wrapping and becoming larger than the event mask resulting in inability to cancel buffer callbacks and timeouts.

*fixed* in streams-0.9.2.3

009. 2007-04-02T11:57:35+0000
ldl was using an incorrect MKDEV command, but when the Stream head attempted to redirect the open to the new (mangled) major device number, it properly returned ENXIO, but did not release a reference to the module. Need to check code paths for this to see where the reference needed to be released.

*known bug*

008. 2007-03-31T05:33:29-0600
When loosening SMP locking, found a bug in the QWANTR handling in getq() and back-enabling in flushq() and flushband(). Both of these were generating false back-enables. The getq() was generating a lot of false back-enables. Whenever getq() found an empty queue it was not only setting QWANTR, but it was back-enabling the queue. The result is that if service procedures are used exclusively (that is, qi_put() always does a putq()), getq() would generate a false back-enable for each message. Also, the enabled queue would generate another false back-enable. Significant performance gains should be noticed.

*fixed* in streams-0.9.2.3

007. 2007-03-16T17:33:20-0600
Jérémy Compostella pointed out an error in strallocpmsg() where it was always assigining M_PCPROTO to messages created with I_FDINSERT.

*fixed* in streams-0.9.2.3

006. 2007-03-14T23:48:26-0600
There appears to be an inode lock imbalance that occurred for several clone error paths in stropen. If the returned major device number does not correspond to a driver, or an snode cannot be acquired for the new entry and the stream head reparented.

*fixed* in streams-0.9.2.2

005. 2007-03-07T15:53:06-0700
Demand loading of kernel modules for clone devices opened, for example, as /dev/streams/clone/mux was requesting module streams-clone-mux and /dev/streams/clone/mux but was not requesting streams-mux or /dev/streams/mux and the modules were failing to demand load.

*fixed* in streams-0.9.2.2

004. 2007-02-26T08:25:09-0700
Jérémy Compostella pointed out error in clone.c. When an automatic clone minor device was unregistered, it was unregistering the modid instead of the major number. This was not noticed because all OpenSS7 drivers have the same modid as major number (strconf does this automatically).

*fixed* in streams-0.9.2.2

003. 2007-02-26T08:25:09-0700
Jérémy Compostella pointed out syntax error in strsched.c that kept synqs from compiling properly.

*fixed* in streams-0.9.2.2

002. 2006-09-24T20:02:00+0000
Discovered asynchronous thread cancellation inconsistencies in libLiS libpLiS by inspection during documentation. isastream(2), fattach(2) were not performing proper asynchronous thread cancellation suppression so that these function contained a cancellation point when the should not.

*fixed* in streams-0.7a.6.rc3

001. 2006-07-05T21:54:49+0000
Fedora Core 5 reports a rwlock bug during udp module unloading as follows:
          BUG: rwlock wrong CPU on CPU#0, rmmod/7515
          Call Trace:
            {rwlock_bug+100}
            {_raw_write_unlock+88}
            {:streams:unregister_strnod+211}
            {:streams:unregister_clone+64}
            {:streams:unregister_strdev+24}
            {:streams_udp:udpterminate+26}
            {sys_delete_module+406}
            {system_call+126}

It appears that unregister_strnod() is scheduling while holding a write lock on cdevsw_lock. This is probably in iput() called within cmin_del.

*fixed* in streams-0.7a.6.rc2

There were a number of places where sleeping functions were called with spin-locks held, causing the CPU awaking from the sleep to sometimes be different from the CPU that took the lock. This was buggy, so I reworked all of these cdev and fmod sections to handle spin locks properly. FC5/SMP on HT no longer reports these bugs.

7.6 Schedule

Current Plan

There are not many things left to be done on the production Linux Fast-STREAMS package. As of the streams-0.9.3 release, performance modifications are complete. The package now exhibits performance on STREAMS-based pipes and TPI drivers that is significantly (factor of 2 or more) superior to that experienced by legacy Linux facilities.

Therefore, the current plan for Linux Fast-STREAMS is largely a maintenance plan. Items on the todo list, below, will be picked up as time permits. The OpenSS7 Project intends to release regularly new versions of Linux Fast-STREAMS that build and validate against upcoming releases of the supported Linux Distributions available from major distributors and upcoming releases of the Linux kernel, both mainline and as patched by major distributors. This release schedule is approximately every 3 to 6 months. More recent corrections and support for new distributions and kernels can be obtained by sponsoring the OpenSS7 Project and obtaining access to the live CVS repository (also available as a git repository).

One development activity in the works for Linux Fast-STREAMS is to provide integral support for more embedded cross-platform development systems such as the Denx ELDK, as well a existing and emerging RT kernels such as Montavista and the upcoming SuSE and RedHat RT kernels. This is a significant undertaking and will only be embarked upon when the OpenSS7 Project is given free access to these RT kernels and distributions.

Things to Do
  • Support for RT kernels. This is a little more than just having the STREAMS scheduler run as a non-RT process kernel thread, which it does now, and which is trivial. (The existing package should compile and run against these kernels with minor modification in this event.)

    More to the point is working the light-weight STREAMS scheduler and service procedures into a prioritized scheme where service procedures run as real-time, yet pre-emptable tasks. In contrast to the current scheme, it is likely that the approach would be to either spawn multiple kernel threads for the STREAMS scheduler at different priorities, or to alter the priority of the STREAMS scheduler in response to the scheduling of specific queues at specific priorities. A design is not really possible until the intricacies of upcoming RT kernels are discovered.

    TODO:
    Provide support for RT kernels.
  • Per cpu data:- I am still using the older approach of using cache line aligned arrays for per-cpu data. This, of course, does not fully utilize NUMA architectures. For NUMA architectures we need to use the per-cpu utilities provided by the 2.6 kernel. I haven't touched converting this yet.

    Also, there are several NUMA supporting STREAMS utility functions (allocb_node, etc.) that need to be supported yet.

    TODO:
    Convert cacheline aligned arrays to NUMA per-cpu data on 2.6 kernels. Complete NUMA supporting STREAMS facilities.
  • Split include/sys/streams/stropts.h by architecture. There is conflicting numbering on the standard STREAMS input-output controls:

    I_SWROPT(7) I_GWROPT(7) I_LIST(7)
    I_FLUSHBAND(7) I_CKBAND(7) I_GETBAND(7)
    I_ATMARK(7) I_SETCLTIME(7) I_GETCLTIME(7)
    I_CANPUT(7)

    System V Release 4 UNIX® vendors use one set and OSF UNIX® vendors use another. Namely HP-UX, OSF/1.2, AIX, Mac OpenTransport use OSF numbering, whereas IRIX, Solaris, UnixWare and others use SVR4 numbering. So, for HPPA, Alpha, PowerPC, we should use the OSF numbering.

    I know that it is a fall-back to the SVR4 way of separating architectural differences by UNIX vendor (if it is HPPA, it must be sold by HP and it must be HP-UX running on it, for example), but even the Linux kernel is victim to this (many ioctls and some errno numbering is split this way). It is completely entrenched in GNU autoconf's config.guess.

    TODO:
    Split include/sys/streams/stropts.h by processor architecture.
  • A similar numbering mismatch occurs for many of the message block types.
    TODO:
    Split include/sys/streams/streams.h by processor architecture.
  • Implement I_EGETSIG(7) and I_ESETSIG(7). These are Solaris enhanced version of the I_GETSIG(7) and I_SETSIG(7) STREAMS input-output controls. The difficulty with their implementation is that the entire signal handling setup inside the Stream head code is geared toward the calling process and needs to be adjusted to be general enough for any process or process group. Until then, Linux file asynchronous I/O is supported.
    PARTLY DONE:
    Wrote the manual pages and added them to the build. Placed function skeletons that return [EOPNOTSUPP] for these functions in the Stream head.
    TODO:
    Implement